student misconceptions celestÉ van niekerk …
TRANSCRIPT
STUDENT MISCONCEPTIONS
IN A HIGH STAKES GRADE 12 PHYSICS EXAMINATION
by
CELESTÉ VAN NIEKERK
DISSERTATION
submitted in accordance with the
requirements for the degree of
MASTER OF EDUCATION
in the
FACULTY OF EDUCATION
at the
UNIVERSITY OF JOHANNESBURG
SUPERVISOR: Dr. U Ramnarain
CO-SUPERVISOR: Dr. JJJ de Beer
NOVEMBER 2011
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DECLARATION
I declare that the work contained in this dissertation is my own and all the sources I
have used or quoted have been indicated and acknowledged by means of references. I
also declare that I have not previously submitted this dissertation or any part of it to any
university in order to obtain a degree.
Signature: __________________________
(Celesté van Niekerk)
Johannesburg
November 2011
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ACKNOWLEDGEMENTS
Firstly, I wish to thank My Lord and Saviour Jesus Christ for granting me all that I
needed to complete this study and for always being with me.
I dedicate this research study to my husband and two sons. Carel, Carel Jnr. and Allan
continuously supported and motivated me throughout this study. I would not have been
able to complete this study without their love, understanding and help.
In particular I would like to thank my supervisor, Dr Umesh Ramnarain, for his
invaluable support and academic guidance. At times when I felt like giving up, he
remained patient. I also would like to thank Dr JJJ de Beer for his contribution as co-
supervisor.
I sincerely thank the National Research Foundation and the University of Johannesburg
for their financial support.
I wish to express my gratitude towards my family, friends and “omgee-groep” for all their
support and encouragement throughout this study. I am especially grateful to my
parents, Maureen and Errol Gunn, and my in-laws, Gerrie and Cielie van Niekerk, for
their encouragement and support throughout this study. Their example of diligence and
dedication has shown me that through perseverance anything is possible.
I also would like to thank Leunis van Rooyen for his skilled editing, done in a very
professional manner.
A special word of thanks and appreciation goes to the teachers and students who
voluntarily participated in this study. Without their co-operation this study would not
have been possible.
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SYNOPSIS
The grade 12 Physical Sciences students of 2008 were the first group of South African
students to write a National Senior Certificate (NSC) on the new outcomes-based
education (OBE) curriculum – the National Curriculum Statement (NCS). Society
scrutinised the performance of students in this high stake examination. The outcome
was disappointing: 71,3% of the students achieved a mark of less than 40%, and 45%
of the group achieved a mark of less than 30%. Concern amongst the educational
community, specifically the Department of Education (DOE), initiated a request for
research into the possible causes of the poor performance by students in this
examination.
There are many factors that affect the performance of students, including the
misconceptions held by students regarding subject content. This study aims to
contribute knowledge about the common misconceptions held by science students
regarding Physics. It also investigates the performance of students in explanation-type
questions and what explanation-types reveal about student misconceptions. The
research design for this study is a content analysis which was carried out qualitatively in
two phases. In the primary phase, a sample of student examination scripts was
analysed. During the secondary phase, interviews were conducted with grade 12
Physical Sciences students and teachers from one school.
The findings of this study are that the following misconceptions are commonly held by
students:
• Heavier objects exert more force on lighter objects during a collision;
• Total external resistance decreases when an external resistor, connected in
parallel, is removed;
• Energy is lost in certain situations;
• A split-ring is found in an AC generator;
• The voltage increases when appliances are added to a multi-plug.
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The misconceptions identified in this study were revealed in explanations that students
constructed in response to examination questions. The data indicate that students
perform 8,4% more poorly in explanation-type questions than in other types of
questions. In addition, 89,3% of student explanations which revealed misconceptions
were genetic, mechanical or functional explanations. These explanation-types exposed
misconceptions about what happens in certain situations, the effect certain physical
properties of objects have on a situation and the function of certain objects,
respectively. In these types of explanations students do not relate the physical evidence
of a situation to the laws of Physics, thereby failing to provide the evidence required in a
scientific explanation. A few student explanations which revealed misconceptions were
rational explanations (1,3%). These explanations revealed misconceptions regarding
the relationship between the physical properties of objects and the laws of Physics.
Currently, the focus of assessment in Physics is on the rote learning of exemplar-type
calculations. The focus of assessment should be changed so that it targets conceptual
understanding. The in-service training of teachers regarding the remediation of
students’ misconceptions is also a recommendation of this study. In addition, since
misconceptions cannot simply be removed from the conceptual framework of a student,
the researcher recommends that the curriculum be narrowed. This will grant teachers
and students the time needed to develop a deeper conceptual understanding of
Physical Sciences.
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TABLE OF CONTENTS
CHAPTER 1
1.1 Introduction 1
1.2 Background to the research problem 1
1.3 Motivation for this study 3
1.4 Aims, objectives or purpose of the inquiry 4
1.5 Research design and methodology 5
1.5.1 Research design 5
1.5.2 Research methodology 7
1.5.3 Data collection 7
1.5.4 Data analysis 8
1.6 Compliance with ethical standards 9
1.7 Outline of the remainder of the thesis 10
CHAPTER 2
2.1 Introduction 11
2.2 Scope of the literature review 11
2.3 Defining the key concepts 12
2.3.1 Pre-knowledge 13
2.3.2 Misconceptions 14
2.3.3 Explanation 15
2.4 Theoretical and conceptual framework 18
2.4.1 Constructivism 18
2.4.2 Social constructivism 19
2.4.3 Conceptual change 21
2.4.4 Classification of explanation-types 25
2.5 Literature review 34
2.5.1 The nature of misconceptions 34
2.5.2 Sources of misconceptions 37
2.5.3 The relationship between language and misconceptions 39
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2.5.4 The relationship between assessment and misconceptions 41
2.5.5 The relationship between context and misconceptions 47
2.5.6 Misconceptions within the field of Physics 49
2.5.6.1 Misconceptions regarding Newton’s Laws on Motion 49
2.5.6.2 Misconceptions regarding momentum and kinetic energy 53
2.5.6.3 Misconceptions regarding the conservation of energy 56
2.5.6.4 Misconceptions regarding electricity and electromagnetism 58
2.5.7 Strategies for the identification and reconstruction of misconceptions 59
2.5.7.1 Concept maps 60
2.5.7.2 Writing activities 61
2.5.7.3 Group discussions and debates 62
2.5.7.4 Practical investigations 64
2.6 Conclusion 65
CHAPTER3
3.1 Introduction 68
3.2 The structure to be constructed – research questions 69
3.3 Beliefs regarding the knowledge to be constructed – epistemology 69
3.4 Research plan for the construction of knowledge– research genre 71
3.5 Construction process - research methodology 72
3.6 Collecting materials – Data collection 73
3.6.1 Exam-script data 74
3.6.2 Interview data 74
3.6.2.1 The rationale behind using interviews to supplement
the exam-script data 74
3.6.2.2 Surveying the site 75
3.6.2.3 Gaining entry and acquiring permission – ethical concerns 75
3.6.2.4 Pre-interview testing for the purposive sampling of
interview participants 77
3.6.2.5 Choosing discursive interviews as the research tool 79
3.6.2.6 Planning the interviews 80
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3.6.2.7 Interview procedure 81
3.6.2.8 Recording the interview data 83
3.6.2.9 Follow-up communication with the interview participants 84
3.7 Constructing evidence – Data analysis 84
3.7.1 Qualitative analysis of the exam-script data 84
3.7.1.1 Identifying the misconceptions 85
3.7.1.2 Designing the classification-grid 86
3.7.1.3 Preliminary classification 87
3.7.1.4 Further classification of student responses
in the sample of exam scripts 91
3.7.2 Quantitative analysis of the exam-script data 91
3.7.3 Computer Assisted Qualitative Data Analysis 92
3.8 Cleaning up the construction site – Data Storage 97
3.9 Conclusion 97
CHAPTER 4
4 .1 Introduction 98
4.2 Student performance in explanation-type questions 98
4.3 Distribution of explanation and non-explanation questions 100
4.4 Describing the different types of misconceptions and their frequency 101
4.5 Five common misconceptions 107
4.5.1 The frequency of five common misconceptions 107
4.5.2 The nature of five common misconceptions 108
4.5.2.1 First common misconception: heavier cars exert more impact
on lighter cars during a collision 109
4.5.2.2 Second common misconception: total external resistance decreases
when an external resistor connected in parallel is removed 114
4.5.2.3 Third common misconception: energy is lost 117
4.5.2.4 Fourth common misconception: a split-ring is found in
an AC generator 120
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4.5.2.5 Fifth common misconception: the voltage increases when
appliances are added to a multi-plug 122
4.6 Other misconceptions 124
4.6.1 Forces acting on two separate interacting bodies can be added,
and may add up to zero, causing the bodies to remain stationary 124
4.6.2 Light objects have less momentum and experience a greater
change in momentum during a collision 125
4.6.3 Momentum is lost or converted into heat or some other form of
energy and kinetic energy and momentum is the same property of motion 126
4.6.4 Misconceptions regarding the internal voltage of a battery 127
4.6.5 The potential difference across resistors connected in parallel remains
constant when one of the resistors is removed 128
4.6.6 DC motors and generators have slip rings and motors and
generators are the same type of machine 128
4.6.7 A cut- off switch works just like a normal switch, it can be switched
off to save electricity 130
4.6.8 Household appliances such as those connected to a multi-plug are
connected in series 130
4.7 Interpretation of the results regarding possible sources of misconceptions 131
4.7.1 The individual as a source of misconceptions 131
4.7.2 Social interactions as a source of misconceptions 132
4.7.3 Language as a source of misconceptions 134
4.7.4 Assessment as a source of misconceptions 136
4.7.5 Context as a source of misconceptions 137
4.7.6 Graphical representation of the possible sources of misconceptions
and their link with misconceptions 140
4.8 Conclusion 143
CHAPTER 5
5.1 Introduction 144
5.2 Summary of major findings 145
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5.2.1 Common misconceptions in Physics 145
5.2.2 Student performance in explanation-type questions 146
5.2.3 What explanation-types reveal about misconceptions 147
5.2.3.1 Explanation-types reveal the nature of misconceptions 147
5.2.3.2 Explanation-types reveal the sources of misconceptions 149
5.3 Implications for teachers and other role-players in education 150
5.4 Critique of the Study 154
5.5 Recommendations for future studies 155
5.6 Summary 156
REFERENCE LIST 157
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LIST OF FIGURES
FIGURE PAGE
Figure 2.1: Dagher and Cossman’s organising scheme for explanations 27
Figure 2.2: The nature of misconceptions – stumbling blocks or
stepping stones 35
Figure 4.1: A bar graph of the performance of a sample of students 99
Figure 4.2: A pie chart of the question-types in the NSC 2008
Physics examination 101
Figure 4.3: A bar chart of the frequency of misconception-types in
a sample of student exam scripts 104
Figure 4.4: A bar graph of the frequency of common misconceptions
as revealed in a sample of student exam scripts 107
Figure 4.5: An examination question on the collision between two cars 109
Figure 4.6: An examination question on a circuit diagram of three
external resistors 115
Figure 4.7: An examination question on a hydro-electric power plant 118
Figure 4.8: An examination question on a generator 121
Figure 4.9: An examination question on a cut-off switch 122
Figure 4.10: A concept map illustrating the relationship between
misconceptions and the causes of misconceptions 141
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LIST OF TABLES
TABLE PAGE
Table 2.1: Comparisons between various authors’ explanation-types 32
Table 3.1: Final misconception classification-grid 90
Table 3.2: Analysis codes 93
Table 3.3: Code families 95–96
Table 4.1: Types of responses identified in a sample of student
exam scripts 103
Table 4.2: Types of student responses classified per examination question 108
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LIST OF APPENDICES
APPENDIX DESCRIPTION PAGE
Appendix A Ethical Clearance from UJ 177
Appendix B Approval form to conduct research from DOE 178
Appendix C Permission letter to conduct research from DOE 180
Appendix D Letter of consent to school principal 181
Appendix E Letter of consent to science teachers 182
Appendix F Letter of consent to parents/guardians 183
Appendix G Letter of assent to students 185
Appendix H 2008 NSC Physics examination 186
Appendix I Possible answers for the 2008 NSC Physics examination 202
Appendix J Pre-interview test 228
Appendix K Extended memorandum for pre-interview test 232
Appendix L Exemplars of classification-grid data 239
Appendix M Questionnaire schedule for interviews 243
Appendix N Transcripts of student interviews 248
Appendix O Transcripts of teacher interviews 322
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LIST OF COMMONLY USED ACRONYMS
C2005: Curriculum 2005
DOE: Department of Education
GDE Gauteng Department of Education
OBE: Outcomes-Based Education
NCS: National Curriculum Statement
NSC: National Senior Certificate
RNCS: Revised National Curriculum Statement
UJ: University of Johannesburg
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CHAPTER 1
INTRODUCTION TO THE STUDY
1.1 INTRODUCTION
This study investigates the common misconceptions held by South African grade 12
(17-18 years) Physical Sciences students, regarding Physics. It also explores the
performance of students in explanation-type questions, the type of student explanations
which reveal misconceptions and what explanation-types reveal about student
misconceptions. The misconceptions identified in this study were extracted from
students’ explanations and were classified according to a framework of explanation-
types generated by Dagher and Cossman (1992). The study is framed in the
constructivist learning theory of social constructivism, according to which knowledge,
including misconceptions, is a social construct.
1.2 BACKGROUND TO THE RESEARCH PROBLEM
The grade 12 students of 2008 were the first group of students to write a national
examination on a curriculum which is underpinned by outcomes-based education
(OBE). This revised curriculum, called the National Curriculum Statement (NCS), was
introduced in 2003, following a series of curriculum-related reforms, including
Curriculum 2005 (C2005).
C2005 had the following three design features: transformational outcomes-based
education (OBE), integration of knowledge and learner-centred pedagogy (Chisholm,
2004). Outcomes-based education focuses on outcomes or results that students need
to achieve; instead of rote learning of subject content it encourages the development of
skills and the use of information on higher levels than recall (Mason, 1999).
Conventional school subjects were replaced by eight learning areas to ensure
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integration of knowledge in and between different disciplines (Cross, Mungadi &
Rouhani, 2002). Learner-centred pedagogy removes the focus from the transmission of
knowledge by the teacher towards the facilitation of co-discovering knowledge together
with the students. From the outset, all three of the design features and C2005 as a
whole received both a large measure of support and criticism from a range of stake-
holders. The major objections were the complex language the OBE curriculum was
written in, the marginalisation of curriculum content, increased administrative burdens
and loss of control by teachers in classrooms due to a learner-centred pedagogy
(Chisholm, 2004; Cross et al., 2002; Jansen, 1998).
A review of C2005 in 2000 directed the way forward to the design of the Revised
National Curriculum Statement (RNCS) in 2002, and the National Curriculum Statement
(NCS) as it is known today (Chisholm, 2005). The NCS is a less radical form of OBE in
that it clearly defines the core knowledge that needs to be covered in each learning
area.
Despite considerable curriculum changes, the 2008 National Senior Certificate (NSC)
Physical Sciences examinations were similar in structure and question-types to papers
based on the previous syllabus (NATED550). The main difference was that new topics
which had been introduced into the curriculum were now examined.
The performance of students in Physical Sciences was poor. Of the 218 156 students
who wrote the paper, 98 060 students (45% of the total) achieved below 30%, and only
62 530 (28,7%) achieved 40% and above (Department of Education, 2008). The poor
performance of Physical Sciences students in the 2008 NSC examinations was of great
concern to both the educational community and to society in general. This lead to the
Department of Education (DOE) requesting that the University of Johannesburg (UJ)
conduct an exam-script analysis to investigate the possible causes of poor performance
in subjects such as Physical Sciences. While factors such as curriculum change, lack of
educational resources and inadequate teacher training inevitably contributed to the
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problem, this study focuses on student misconceptions and the nature of student
explanations.
1.3 MOTIVATION FOR THIS STUDY
Poor results in Physical Sciences education have often been ascribed to students’
misconceptions. Students come to school with a collection of life-experiences, ideas
and explanations for the physical world in which they live (Driver, 1983; Posner, Strike,
Hewson & Gertzog, 1982). These concepts or ideas are commonly referred to as
preconceptions. Many of these experientially and socially constructed conceptions are
different to the scientific concepts that are taught in the Physical Sciences classroom,
so they are referred to as misconceptions. Since these misconceptions work in the
context of the students’ observations, students “cling rigidly to their current beliefs”
(Pine, Messer & St. John, 2001, p.83) and are hesitant to accept scientific concepts.
During examinations, students formulate responses based on their understanding.
Since misconceptions form part of their understanding and differ from scientific
conceptions, students formulate incorrect responses which negatively affect their
performance.
Alternative ideas or misconceptions also arise in the classroom when students interact
with their peers, teachers and learning material such as textbooks. In these interactions
students may be presented with incorrect conceptions, which they then make their own.
Sometimes teachers and textbook writers use analogies to illustrate a concept and then
students may take these analogies too far and be unable to separate it from the original
subject content; other students only remember the analogy and struggle to remember
the original content (Thiele, Yenville & Treagust, 1995). When students apply concepts
which they have learnt in the class or from experience to situations where they do not
apply, such over-generalisations also constitute misconceptions. Students may even
take a correct explanation and construct their own incorrect conception that makes
sense to them. Students’ misconceptions often go undetected and may only reveal
themselves when students write a test or an examination. Since misconceptions are
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also formed in class and are not easily recognised, it is important to increase teacher-
awareness of misconceptions by identifying specific misconceptions held by students.
In addition, Pine et al. (2001) warn that even when teachers are aware of student
misconceptions they do not necessarily have the time to investigate how their students
developed them or how to address them. Therefore it is important not only to identify
misconceptions but also to further investigate their nature, thereby constructing
knowledge that could be used in the design of remediation strategies. According to
Zuzovsky and Tamir (1999, p.1101) “Explanations are demonstrations of understanding
and provide a window to a person’s thinking.” Hence, in order to determine more about
the nature of student misconceptions, which form part of a students’ understanding, this
study explored student explanations and their connection with the misconceptions
revealed in them.
The new curriculum is student-centred as it conceives of the student as one who
constructs and applies scientific knowledge (Department of Education, 2003). The
teaching and learning approaches implicit in the new curriculum are largely founded
upon the basic tenets of social constructivism, according to which knowledge is initially
attained through social interactions after which it is internalised (Vygotsky, 1978). In
adopting a social constructivist approach in classrooms, it was expected that students
would have the opportunity to express and exchange ideas with peers and the teacher
on a particular topic. Students would then be in a position to test the degree of fit
between their preconceptions and the scientific explanations of phenomena and
reconstruct their conceptions where necessary. However, the poor results of 2008
indicate that misconceptions continue to form part of students’ conceptual frameworks
and may not be receiving the required attention.
1.4 AIMS, OBJECTIVES OR PURPOSE OF THE INQUIRY
The aim of the study is to contribute knowledge about the common misconceptions held
by Physical Sciences students, as evidenced by the 2008 NSC Physics examination. I
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also aim to investigate the performance of students in explanation-type questions, the
types of student explanations which reveal misconceptions and also what explanation-
types reveal about student misconceptions. In this regard the following research
questions were formulated:
1. What are the common student misconceptions that are revealed in a high stakes
Physics examination?
2. How do students perform in explanation-type questions?
3. What do explanation-types reveal about student misconceptions?
1.5 RESEARCH DESIGN AND METHODOLOGY
In this section I will commence by discussing the research design of this study, then I
will discuss the methodology employed to carry out the study as designed. Next I will
discuss the data collection and analysis methods which enabled me to collect evidence
regarding student misconceptions as revealed in explanations.
1.5.1 Research design
An appropriate research design and methodology yields evidence which accurately
addresses the research problem. Mouton’s advice (2009) regarding the selection of a
research design and methodology is that researchers first consider what beliefs they
hold regarding the evidence they are searching for as well as what type of evidence
they are searching for.
I approached this study from the belief that knowledge, including explanations and
misconceptions, is not merely transferred to the student but rather co-constructed by the
student and various social role-players (Vygotsky, 1978). In other words, I framed this
study in the epistemology of social constructivism.
I employed Mouton’s three pairs of design logics (2009), which are formulated to assist
researchers in deciding what type of evidence they require so that a suitable research
design can be selected. Mouton’s first pair of design logics is contextualisation versus
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generalisation. Contextualisation refers to the generation of research data which is more
detailed and focussed on a small number of cases. Generalisation refers to the
generation of research data which is applicable to a wider population. For the purpose
of this study I chose to focus on a small number of cases for a more in-depth
investigation, thereby situating this study in the logic of contextualisation.
Mouton’s second pair of design logics is discovery versus validation. Discovery refers to
the generation of research data through a process of discovery, whereas validation
refers to the generation of research data through the testing of a hypothesis. I chose to
discover more about misconceptions rather than to test a specific hypothesis regarding
misconceptions.
Mouton’s third pair of design logics is synchronicity versus diachronicity. Synchronicity
refers to the generation of data which represents a process, whereas diachronicity
refers to the generation of data which represents a specific moment in time. I chose to
generate data which would represent the development of student misconceptions and
explanations over a period of time, in other words ― the logic of synchronicity.
After using Mouton’s design logics to determine that the evidence I required for this
study would need to come from a small number of cases which I aimed to explore in-
depth, I was in the position to select a research design for this study. A sample of
student exam scripts from the 2008 NSC had been made available to me and I realised
that an exploration of the textual content in these scripts would expose student
misconceptions. Therefore, I decided to select content analysis as the research design
for this study. According to Berelson, as quoted by Breecher (1993, p.15), content
analysis is “a research technique for the objective, systematic, and quantitative
description of the manifest content of communication.” Therefore, a content analysis
would allow me to construct a thorough description of student misconceptions evident in
their explanations.
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In order to further illuminate student misconceptions I decided to also conduct a content
analysis of interview data, which I collected and analysed in a second phase of this
study. According to White and Marsh (2006), interview data that adds valuable evidence
with regard to the research question is suited to content analysis.
1.5.2 Research methodology
Deciding what methodology I would use to carry out the content analysis followed next.
Since this study aims to generate evidence regarding the process by which students
construct explanations and misconceptions, a qualitative methodology suits the
research design. Bogdan and Biklen (1998, p.38) explain that “The qualitative
researchers’ goal is to better understand human behaviour and experience. They seek
to grasp the processes by which people construct meaning and to describe what those
meanings are.” A qualitative methodology would not only allow me to better understand
the misconceptions that students construct, but would also allow me to position myself
inside the social world (Denzin & Lincoln, 2000) of the student as a co-constructor of
meaning. Even though my research adopted the form of a qualitative study, I collected
both numeric and textual data in order to induce or construct a description of student
misconceptions as revealed in their explanations.
1.5.3 Data collection
The data collection of both the numeric and textual data took place during the two
phases of this study. In the primary phase I collected data from a random sample of 921
grade 12 Physics exam scripts, which were provided by the Gauteng Department of
Education (GDE). These scripts were made available as a result of a script analysis
project being conducted at UJ for the GDE. I only collected data from the student
responses to explanation-type questions, as calculation-type questions do not provide
descriptions of students’ misconceptions and I aimed to investigate what explanations
reveal about misconceptions.
The aim of the second phase of this study was to further clarify the data collected from
the exam scripts by conducting interviews with grade 12 students and teachers. During
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interviews I would be able to probe students’ ideas regarding the misconceptions
revealed in their exam scripts. However, since I did not have access to the students of
2008, I needed to identify students from a later cohort who displayed the same
misconceptions as those presented by the 2008 cohort. Selecting a sample of research
participants for a specific purpose, such as finding students with similar misconceptions,
requires a purposive sample. In order to enable the selection of the purposive sample, I
administered a test to a group of 2010 grade 12 Physical Sciences students from a
school which is conveniently located close to my place of work. The test consisted of
the same explanation-type questions, extracted from the 2008 NSC Physics paper, that
I had collected data from in the exam scripts. After the students wrote the test I
analysed the test scripts in the same manner as the 2008 exam scripts. This enabled
me to identify students who displayed the same types of misconceptions as the 2008
cohort of students. These students constituted the sample for my interviews. The
interviews provided a richer description of the misconceptions and were also used to
seek an explanation of how students develop these misconceptions. Thereafter, the
teachers of these students were interviewed. The teachers were asked for their opinion
on the misconceptions held by their students, possible sources of misconceptions and
about the strategies they are using to address these misconceptions.
1.5.4 Data analysis
In this study the data analysis also took place in two phases. First, a qualitative and
quantitative analysis of the exam-script data was conducted. Then a qualitative analysis
of the interview data and its relationship with the exam-script data followed.
The qualitative analysis of the exam scripts commenced with the identification of
misconceptions. Student responses were compared to the memorandum. Responses
that differed from the correct answer were classified as misconceptions. Since this study
aims to investigate the relationship between misconceptions and explanations, I then
designed a grid which would be employed to categorise different types of explanations.
The categories of explanation-types were taken from the Dagher and Cossman (1992)
framework of explanation-types. Each exam-script response constituting a
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misconception was then categorised according to the type of explanation in which the
misconception had appeared. I tested the reliability of my analysis by asking another
researcher and two Physical Sciences teachers to apply the framework in categorising
student misconceptions in the exam-scripts. Through discussion we attained consensus
with regard to the classification of misconceptions found in the exam-scripts. Intercoder
reliability was 86%.
The quantitative analysis of the exam scripts commenced with a calculation of the total
number of each type of misconception and the total number of misconceptions all
together. I also calculated the average percentages achieved by the students for
explanation-type questions and for non-explanation-type questions in the examination.
After the interviews with the students and teachers I used the qualitative analysis
methods of coding and clustering to construct findings regarding the students’
misconceptions. Coding and clustering involves the breaking-down, conceptualisation
and reconstruction of the data (Strauss & Corbin, 1990). In order to reconstruct or
recontextualise the data I needed to make meaning of the data. Making meaning of the
data or constructing findings involves discussing the clusters or themes and making a
case as to how these themes are the answer to the research questions (Henning et al.,
2004). In order to improve the management of the data analysis, I used the computer
software Atlas.ti.
1.6 COMPLIANCE WITH ETHICAL STANDARDS
In my study I have complied with the ethical standards of the university. I have done this
by informing and seeking permission from the head office (Appendix B) and relevant
district office of the GDE to conduct research at a school (Appendix C). Permission for
the analysis of the 2008 grade 12 scripts was granted by way of a script analysis project
that was commissioned by the GDE. Written consent was obtained from the school
principal, teachers and parents of students who participated in the study (Appendix D –
F). Students who agreed to participate signed an assent letter (Appendix G). The letters
10
informed participants of the background and purpose of the study. The potential benefits
of the findings of this study were pointed out to the participants. An explanation was
also provided regarding the nature and duration of the test and interviews. The identity
of the participants and the information obtained was kept confidential. Participants were
assured that the study would not expose them to harm in any way. Participants were
made aware that their participation is voluntary and that they could choose to withdraw
from the study at any time. The teachers and students received feedback on the
findings of the study. It is expected that the findings will inform teachers and students
about common misconceptions and how these misconceptions develop. This
information and the recommendations emanating from the study could be of value to
them in addressing these misconceptions. Data was stored in such a manner as to
ensure the confidentiality of participants and it will be kept under lock and key for two
years after the study, and thereafter it will be destroyed. The letter of ethical clearance
that was obtained for this study is included as appendix A.
1.7 OUTLINE OF THE REMAINDER OF THE THESIS
In this section I will discuss briefly how my thesis will unfold and I will indicate the main
topics that I will discuss in each of the remaining chapters.
In chapter two I have compiled a literature review of what research says regarding
student misconceptions.
Chapter three is a discussion of my research design and the method which I used to
collect and analyse data which would inform my research question.
Chapter four is a discussion of the data collected and an interpretation of what the data
means.
Chapter five is a summary of my findings, implications for teachers and other role-
players and a critique and summary of this study.
11
CHAPTER 2
LITERATURE REVIEW, THEORETICAL AND CONCEPTUAL FRAMEWORK
2.1 INTRODUCTION
The purpose of this chapter is to discuss the research trends and theories that form the
theoretical framework or scaffolding of my research problem. My research aims to
identify common student misconceptions as revealed in a Physics examination, and to
classify these misconceptions according to the type of explanation offered. Since there
are many theories regarding misconceptions and explanations, I will commence this
chapter by discussing the scope of my literature review. Thereafter, I will define the
concepts of pre-knowledge, misconceptions and explanations which are central to my
study. I will also discuss how the learning theories of constructivism, social
constructivism and conceptual change explain that knowledge, including
misconceptions, is constructed and re-crafted by a student, together with society. Next, I
will discuss the explanation classification framework which forms the conceptual
framework of my study. I will continue by reviewing literature on the nature of
misconceptions, the sources of misconceptions, the relationship between
misconceptions and language, assessment and context. I will list common
misconceptions held within the field of Physics as identified in previous studies. The
identification and remediation of misconceptions should form part of teaching, hence I
will discuss contemporary teaching methods designed to address misconceptions.
Finally, I will conclude the chapter with an overview of the main conclusions that I have
reached on the basis of my literature review.
2.2 SCOPE OF THE LITERATURE REVIEW
There is an abundance of literature and research studies on the topic of
misconceptions, thus it is necessary for me to discuss the scope of my literature review.
From my initial literature review it became evident that students enter the classroom
12
with preconception and then continue to construct concepts which often differ from the
accepted scientific concepts. It also became evident that strategies for the remediation
of misconceptions have been the topic for many research studies over the last few
decades. Initially strategies for the remediation of misconceptions were based on the
learning theories of empiricism and behaviourism, and the removal and replacement of
misconceptions was proposed. However, traditional studies showed that
misconceptions are resistant to change, even after the use of various teaching methods
designed to remove misconceptions. Contemporary learning theories, such as
constructivism, social constructivism and conceptual change, offer an alternative view
on the nature and remediation of misconceptions. Studies on constructivist teaching
strategies have shown them to be effective in addressing misconceptions. Therefore, I
will focus my literature review on the theories of constructivism, social constructivism
and conceptual change, and on the alternative views which these theories offer with
regard to the nature and remediation of misconceptions.
Research studies on misconceptions are not only based on many different learning
theories but also on many different subject fields. Since my study aims to identify
misconceptions as revealed in a high school Physics examination, I will focus my
literature review on studies that investigate misconceptions within the field of high
school Physics. I have done this because misconceptions, sources of misconceptions
and some of the remediation strategies are more subject specific.
My study also aims to investigate how misconceptions can be classified according to
the type of explanation offered. Therefore, the scope of my literature review also
includes studies on various types of explanations using the Dagher and Cossman
(1992) framework of explanation-types.
2.3 DEFINING THE KEY CONCEPTS
The key concepts that I investigated during this study are pre-knowledge,
misconceptions and explanations. In this section I will review information regarding
13
these concepts from previous studies, and supply working definitions of these concepts
for the purpose of this study.
2.3.1 Pre-knowledge
The word pre-knowledge consists of the prefix: pre, meaning before, and the root:
knowledge, meaning information, facts or understanding (Sinclair, Hanks & Fox, 1988).
Hence I will use the following definition for this study: pre-knowledge is a prior
understanding. These prior understandings are also referred to as “preconceptions”
(Morrison & Lederman, 2003, p.849). According to Novak (2004, p.23), a conception or
concept can further be defined as “perceived regularities or patterns in events or
objects, or records of events or objects, designated by a label, usually a word.”
Students come to school with a collection of prior understandings in the form of life
experiences, ideas and explanations of the physical world in which they live (Posner et
al., 1982). Mintzes, Wandersee and Novak (1998, p.75) explain that “students develop a
set of well-defined ideas about natural objects and events before they arrive at the
classroom door.” Children also construct these ideas when asking family members or
acquaintances about how and why things happen (Kibuka-Sebitosi, 2007). Students
also construct pre-knowledge inside the Physical Sciences classroom. During the
various teaching and learning activities that take place at school, students construct
their own version of the scientific concepts under discussion. These understandings
develop as the student engages with the learning material, the teacher, and with other
students (Mintzes, et al., 1998; Morrison & Lederman, 2003).
Pre-knowledge, constructed both outside and inside the school environment, forms the
foundation for constructing new knowledge (Smith, diSessa & Roschelle, 1993). Novak
(1998, p.xix) quotes Ausabel’s well-known reference which explains that “the most
important single factor influencing learning is what the student already knows.” Moore
and Harrison (2004, p.14) add that “teaching strategies that explore prior knowledge are
essential to ascertain the kinds of images and ‘talk’ that children use when constructing
14
their ideas about science and how ‘things’ work.” Hence it is vital that teaching is based
on the students’ conceptual networks (Glaserfeld, cited by Mintzes et al., 1998, p.45).
2.3.2 Misconceptions
Some of the pre-knowledge or preconceptions constructed by students are different to
the scientific concepts that are taught in the Physical Sciences classroom (Akku,
Kadayifçi, Atasoy & Geban, 2003; Dekkers & Thijs, 1998; Eryilmaz, 2002; Smith et al.,
1993; Tekkaya, 2003). Traditionally preconceptions that differ from scientific
conceptions were viewed as incorrect ideas, hence the introduction of the term
misconception, which means “wrong idea” (Sinclair et al., 1988, p.497). Misconceptions
were considered to be an obstacle which hinders learning and which needs to be
removed and replaced with the correct concepts (Palmer, 2001; Tytler, 1998). However,
studies have reported that these misconceptions are very resistant to instructional
change (Clough & Driver, 1986; Eggen & Kauchak, 2004). Akku et al. (2003, p.210)
explain that “students persist in giving answers consistent with their misconceptions
even after large amounts of instruction.”
Conversely, contemporary studies have a different perspective on the status of
students’ preconceptions which differ from scientific conceptions (Dekkers & Thijs,
1998; Tytler, 1998). Smith et al. (1993, p.153) argue that “learning requires the
engagement and transformation of productive prior resources, and misconceptions,
when taken as mistakes, cannot play that role.” In other words, student’ preconceptions,
which differ from scientific conceptions, are also seen as productive prior resources
(Pine et al., 2001), conceptions under transformation, and “anchoring conceptions” upon
which new knowledge is built (Clement, Brown & Zietsman, 1989, p.554). Hence, new
terminology was introduced to match the new status of student preconceptions which
differ from scientific conceptions. This new terminology is profuse and includes terms
such as: alternative conceptions, naïve beliefs, alternative beliefs, alternative
frameworks, naïve theories, non-scientific ideas, children’s beliefs, children’s science
and informal science conceptions (Hamza & Wickman, 2009; Smith et al., 1993; Tytler,
15
1998). These differing perspectives regarding the status and nature of misconceptions
will be discussed in greater detail in section 2.5.1.
It is, however, necessary for me to clarify my position regarding the status of
misconceptions in order to define the concept of misconception. The theory of
constructivism, which I have chosen as the framework for this study, emphasises that
“prior knowledge is the primary resource for acquiring new knowledge” (Smith et al.,
1993, p.151). Therefore, I will take the position that misconceptions are conceptions
under transformation, which should not be viewed as incorrect but rather as
preconceptions that need to be refined.
Before I finally define a misconception, it is important to note that not all mistakes are
misconceptions. Students may appear to hold a misconception when actually they are
merely using the wrong language to express their idea (Clerk & Rutherford, 2000;
Schuster, 1983). Strike (1983, p.188) argues that a misconception should be viewed as
“an assumption that is structurally important in the student’s belief system. It is
something that generates mistakes.” I will use the following definition for this study: a
misconception is a believable conception which differs from the corresponding
scientific conception. Since I view misconceptions as conceptions under trans-
formation, as opposed to incorrect conceptions, I will use a variety of terminology —
including alternative conceptions and alternative constructs—interchangeably. I will also
continue to make use of the term “misconception” despite my constructivist position as it
remains a common term that researchers employ and that teachers are well-acquainted
with.
2.3.3 Explanation
The term explanation has many synonyms, such as clarification, description,
commentary, account, reason, justification, answer, defence and vindication (Hawker &
Waite, 2001). Upon examining these synonyms it becomes clear that there are subtle
differences between them. These differences allude to the fact that a variety of
meanings are attached to the term explanation. Berland and Reiser (2008, p.27) affirm
16
that “no single definition of explanation can account for the range of information that can
satisfy a request for an explanation.” Hence, they treat the term “explanation” as an
encompassing term meaning both describe and rationalise and define an explanation as
an expression of what happened, and/or a clarification of why an event happened in the
form of reasons, evidence and logical argument. Gilbert, Boulter and Rutherford (1998a)
explain that there are many types of explanations and that the explanation which is
given depends on the type of question which is asked. I will discuss the classification of
various types of explanations in greater detail in 2.4.4. On the other hand, Zuzovsky and
Tamir (1999) argue that explanation is different from scientific description, in that
explanation brings about a different level of understanding. Also during the construction
of an explanation information is connected, whereas in a description the information is
fragmented. Scriven (1998, p.53) agrees that there is a difference between explanation
and description but argues that explanation is not “something ‘more than’ or even
something intrinsically different from informing or describing.” The difference lies in the
context in which the explanation is constructed. What would be classified as a
description in one context may be classified as an explanation in another context and
vice versa. Also, what differentiates an explanation from a description is the “known or
inferred state of understanding and the proposed explanation’s relation to it” (Scriven,
1998, p.53). Since both descriptions and explanations can increase a persons’
understanding, depending on the degree to which they are complete and correct, I will
define an explanation as follows: an explanation is a detailed description of what
happened and/or a rationalisation of why something happened.
The process of constructing explanations does amplify one’s understanding and
“Articulating and learning go hand in hand, in a mutually reinforcing feedback loop”
(Sawyer, as cited by Berland & Reiser, 2008, p.29). Also, the construction of
explanations necessitates students to find reasons and evidence for a certain claim or
event and then to align the evidence and claims. This process of constructing
explanations not only develops the student’s understanding of the subject matter,
(Berland & Reiser, 2008) but also exposes the student’s current understanding (Sevian
& Gonsalves, 2008) or misunderstanding (Graesser et al., 1996; Sevian & Gonsalves,
17
2008). Zuzovsky and Tamir (1999, p.1101) explain that “Explanations are
demonstrations of understanding and provide a window to a person’s thinking.” Hence,
student explanations can be used both during informal and formal assessment to
assess a student’s understanding, in order to inform consequent teaching activities.
According to Vygotsky, as cited by Sevian and Gonsalves (2008, p.1443), “the ability to
explain one’s understanding is often a measure of whether or not that thing has been
effectively learned.” Graesser et al. (1996, p.20) echo this sentiment by stating that
“explanatory reasoning questions have been a popular litmus test of whether students
are truly understanding material, as opposed to merely memorizing explicit information.”
Explanation is also regarded as an important learning outcome and assessment
standard in the National Curriculum Statement for Physical Sciences. The second
learning outcome for Physical Sciences states that “The student is able to state, explain,
interpret and evaluate scientific and technological knowledge and can apply it in
everyday contexts” (Department of Education, 2003, p.13). Also one of the assessment
standards, that falls under the second learning outcome, states that the student needs
to be able to “Express and explain prescribed scientific theories and models by
indicating some of the relationships of different facts and concepts with each other”
(Department of Education, 2003, p.27). Hence, explanations are requested in
examinations and in the 2008 NSC Physics examination (Appendix H) students were
prompted to use principles of Physics to explain why certain events occur.
The rationale and evidence required in a scientific explanation are scientific theories
and models (Giere quoted by Gilbert et al., 1998a). This makes constructing scientific
explanations an even more complex task as students are accustomed to using their
own reasons and theories when supplying explanations, especially when the event
under explanation is framed in an everyday context. After all, “Explaining is a human
activity whose practice long antedated the rise of modern science” (Giere quoted by
Gilbert et al., 1998a, p.92). Even when assessors clarify their expectations in
explanation-type questions, students provide no reasons or incomplete reasons
because they are not used to answering such questions and because there is a “lack of
18
consistency in how the terms explain and describe are used in teaching materials”
Horwood (in Dagher & Cossman, 1992, p.362). Also, many types of explanations are
used and required in Physical Sciences education which complicates the use of
explanations, together with the variety of scientific theories and terminology which must
be mastered in order to construct these explanations. Hence, it is necessary for
teachers to educate students regarding the “basic patterns of explanation” (Zuzovsky &
Tamir, 1999, p.1120). The use of both verbal and written explanation activities, in order
to develop understanding and remediate misconceptions, is discussed in greater detail
in section 2.5.7. Finally, explanations remain an essential assessment tool,
misconception identification tool and, even more so, a teaching and learning tool for
both teachers and students.
2.4 THEORETICAL AND CONCEPTUAL FRAMEWORK
My study is supported by a theoretical and conceptual framework. Henning et al., (2004)
explain that a theoretical framework situates the study within the research field, and it
reveals the researchers’ biases or beliefs regarding their study. Since misconceptions
are formed during learning experiences, both informal and formal, this study is
theoretically framed by the constructivist learning theory of social constructivism. The
conceptual framework for my study is a classification of explanation types by Dagher
and Cossman (1992), which I used to classify student misconceptions. Since social
constructivism is related to constructivism, I will start by discussing constructivism, then
social constructivism and then conceptual change. I will continue by discussing Dagher
and Cossman’s classification of explanation types.
2.4.1 Constructivism
During the last quarter of the 20th century constructivism gradually displaced empiricist-
behaviourist-dominated learning theory, which viewed learning as the direct transfer of
knowledge from teacher to student through the senses (Klassen, 2006). According to
Klassen (2006, p.826), constructivist learning theory stands in direct opposition to the
traditional notion of learning as the transferral of knowledge, as it views the student as
19
“actively reconstructing new information in order to assimilate it into existing knowledge
structures.” Constructivism was greatly influenced by the work of Piaget and Ausubel.
According to Piaget (1970, p.2) “Scientific thought, then, is not momentary, it is not a
static instance; it is a process. More specifically, it is a process of continual construction
and reorganisation.” Ausubel (in Klassen, 2006, p.829), argued that learning becomes
more long-term when “linked in a non arbitrary substantive fashion to existing
knowledge structures of the brain.” Constructivism clearly emphasises the connection of
new knowledge to a student’s existing knowledge structures (Mintzes et al., 1998). Also,
because misconceptions form part of a student’s existing knowledge structures, they
influence the manner in which new information is processed and reconstructed. Hence,
constructivism clarifies how misconceptions affect learning and thus forms the
theoretical framework for most of the current research in the field of misconceptions
(Palmer, 2001), including this study.
Constructivism is a diverse theory of learning which includes multiple views on
knowledge construction (Gravett, 2005). Individual or radical constructivists focus on the
individual’s construction of knowledge (Klassen, 2006). I agree that student constructs
are personal and that students’ understandings or constructions will differ. However, I
argue that students do not construct conceptions in a vacuum, and both social role-
players and social factors have an effect on an individual’s knowledge constructs.
Therefore social constructivism will be particularly useful in this study on the
construction of misconceptions.
2.4.2 Social Constructivism
The elementary academic orientation for social constructivism was provided by Lev
Semenovich Vygotsky. Vygotsky (1978) argued that people initially attain knowledge
through social interactions, thereafter it is internalised through reconstruction in the
mind of the individual. According to Vygotsky (1978), a student’s learning ranges
between the conceptual constructions that a student is able to construct individually and
the conceptual constructions that a student constructs with the help of a more informed
20
person. Vygotsky (1978, p.86) named this range of learning “the zone of proximal
development.”
Since cognitive development depends on both the individual and the more informed
person, teachers can influence student constructions. They can do this by the manner in
which they convey the information, the aspects they highlight and the examples and
thought-pictures that they sketch. If the teacher allows for group discussion of the
information, these discussions will also affect the understanding constructed by each
student, in fact “peers are sometimes more effective than adults in helping an individual
construct meaning because peers are at a similar developmental levels” (Jones &
Carter, 1998, p.264). Matthews (1998, p.3) reiterates that social constructivism
“stresses the importance of the group (be it the immediate classroom or the wider
culture) for the development and validation of ideas.” Mathews (1998, p.56) also states
that social constructivist theories make use of terminology such as “social negotiation”,
which emphasises the co-construction of concepts by students and society. Prawat and
Floden (1994, p.40) explain that negotiation involves “consensus building” and “skilfully
overcoming obstacles.” Reaching consensus occurs when students share their personal
constructions and reason with their teachers and peers in order to construct new
knowledge which resembles expert knowledge. When teachers are aware of students’
personal constructions they can overcome obstacles, such as misconceptions, by
designing activities which will “be able to ground new material in that portion of the
student’s intuition which is in agreement with accepted theory” (Clement et al., 1989,
p.554). Mintzes et al. (1998, p. 50) add that teachers are “middlemen” bridging the
differences between the student’s existing knowledge structures and new knowledge.
It is not only the dialogue of validation, negotiation and mediation that takes place
directly between teachers, students and their peers that influences learning. Learning
tools such as textbooks, the learning context and environment, social language and
culture also add their voice in influencing student constructs (Gravett, 2005; Zuzovsky &
Tamir, 1999). Vygotsky (1962, p.153), particularly, emphasised the effect of language
on student constructs by explaining that “Words play a central part not only in the
21
development of thought but in the historical growth of consciousness as a whole.”
According to Scott, Asoko and Leach (2007), Vygotsky regarded the social tools of
communication as resources for personal thinking. Hence, students’ conceptual
constructs will be influenced by their language resources, specifically their lack thereof.
This is especially the case when students are receiving a formal education in their
second language (Kibuka-Sebitosi, 2007), such as the majority of students in this study.
In addition, students’ unfamiliarity with scientific language and/or confusion by the
discrepancies between everyday social language and scientific language will affect their
conceptual constructs and may lead to misconceptions. I will discuss the effect of
language on student constructs in greater detail in section 2.5.3.
2.4.3 Conceptual change
If this study was framed in the empiricist theory of transferral of knowledge, I would
proceed by discussing how teachers could erase misconceptions (Strike, 1983).
However, literature has shown that misconceptions are resistant to teaching methods
aimed at replacing misconceptions (Clough & Driver, 1986). Hence, this study which is
framed in the constructivist learning theory of social constructivism, promotes a more
contemporary view for dealing with misconceptions, namely that of conceptual change.
According to Strike (1983, p.20) conceptual change theory views “learning as the
modification of current concepts” and clarifies how misconceptions can be changed.
Since misconceptions form part of students’ current concepts they can be modified or
changed during the construction of new knowledge. Also, since teachers are co-
constructors of knowledge they can assist students in modifying misconceptions.
Conceptual change theory also clarifies how misconceptions are formed. According to
conceptual change theory, learning can be viewed as the recrafting of pre-knowledge
and misconceptions are formed when students change their pre-knowledge in an
incorrect manner.
In order to better understand how students change their pre-knowledge, both during the
formation and during the remediation of misconceptions, it is necessary to understand
22
the various levels of change that may take place. At the most elementary level, students
can simply add new concepts onto their existing knowledge framework (Smith, 2007;
Tyson, Venville, Harrison & Treagust, 1997). These new concepts may be incorrect or
linked incorrectly, resulting in misconceptions. At a more advanced level, when new
concepts are incommensurable with students’ current concepts, students reorganise
their current concepts. Posner et al. (1982) label this more radical form of change as
“accommodation”. This radical form of change needs to happen in order to remediate
misconceptions, hence I will continue by discussing the conditions for accommodation.
The four conditions for conceptual change as identified by Posner et al. (1982, pp.216-
222) are: “dissatisfaction with existing conceptions”; “intelligibility of a new conception”;
“initial plausibility of a new conception”; and “fruitfulness of a new conception”. Students
first need to experience difficulties with an existing concept before they will abandon it.
These difficulties often occur in the form of an anomaly or inconsistency which the
student cannot make sense of. Anomalies can lead to a reorganisation of a student’s
misconceptions. However, the student could alternatively choose to discard the
anomaly or to regard the observations and experimental findings backing the anomaly
as irrelevant. Students may alternatively group new concepts apart from pre-concepts
as if “Science doesn’t have anything to do with the ‘real’ world”, or change the new
concepts so that they fit in with the student’s existing concepts (Posner et al., 1982,
p.221). Hence, it is important to seek out and use effective anomalies. Secondly,
students need to experience the new conception as intelligible; in other words, they
need to understand and make sense of the new conception. This involves more than an
understanding of the component terms and symbols; it includes the internal construction
of a representation of the new theory. Thirdly, students need to experience the new
concept as believable or plausible. New concepts become plausible when they appear
to have the capacity to solve problems and anomalies that pre-concepts cannot resolve,
and when the new concepts fit in with what the student believes and has experienced.
Lastly, students need to experience the new concept as fruitful. In other words, the new
concepts should communicate useful applications and discoveries. Posner et al. (1982,
p.223) warn that these conditions may not be met in a linear order and that although
23
they describe accommodation as a radical change, it “rarely seems characterized by
either a flash of insight, in which old ideas fall away to be replaced by new visions, or as
a steady logical progression from one commitment to another. Rather, it involves much
fumbling about, many false starts and mistakes, and frequent reversals of direction.”
Posner et al. (1982, pp.214-215) also identify five different types of student
preconceptions that influence the construction of new concepts and misconceptions and
the reconstruction of misconceptions. Firstly, “anomalies” affect conceptual change,
because the nature of inconsistencies in existing concepts will influence the nature of
the replacement or reorganising concepts. Secondly, the “analogies and metaphors” in
the student’s conceptual ecology will help to make new concepts more understandable.
Thirdly, the student’s inner “epistemological commitments” regarding what the student
believes about the nature of knowledge and explanations, will influence the plausibility
of new concepts. According to Nussbaum, Sinatra, and Poliquin (2008), students are
more likely to change their misconceptions if they view knowledge as flexible. Fourthly,
the student’s inner “metaphysical beliefs and concepts”, in other words what the student
believes about the incontestable nature of the universe, will also influence the
plausibility of new concepts. Lastly, the “other knowledge” that forms part of the
student’s conceptual ecology may compete against new concepts for a place in the
student’s knowledge framework.
Posner et al. clearly focus on how the student’s inner epistemological perspective
influences conceptual change and on the rational nature of learning. Research on
conceptual change has been approached from other perspectives. Chi, Slotta & De
Leeuw (1994), for example, focus on the student’s ontological perspective, that is, the
student’s view of reality or the outside world. According to this perspective, conceptual
change involves the student changing the ontological category of a concept from the
incorrect non-scientific ontological category to the scientifically correct ontological
category (Chi et al., 1994; Tsui & Treagust, 2004). For example, students who think of
heat as a material substance need to make ontological changes to their conceptual
framework (Chi et al., quoted by Tyson et al., 1997).
24
Another perspective, which cannot be ignored when one is seeking to find ways of
remediating misconceptions, is that motivational and affective variables influence
learning and conceptual change. Pintrich et al., as quoted by Duit and Treagust (2003),
emphasise that a student’s interests, attitudes, ambitions, self-worth, control beliefs,
expectations, enthusiasm and needs, together with the classroom environment affect
learning. Zusho, Pintrich and Coppola (2003) emphasise three motivational components
which need to be taken into consideration in order to stimulate conceptual change. The
first is self-worth; students who believe that they are capable of effectively completing
an activity behave in ways that promote learning. The second motivational component is
assignment value attitudes; students who believe in the value of the assignment given
to them or in the course material engage in deeper levels of conceptual change. The
third motivational component is goal orientation; students who set a goal towards
achieving assignment competence have improved motivation, which in turn positively
affects learning. The last motivational component is affect. Zusho et al., (2003) define
affect in terms of interest and anxiety. Students who are interested in a subject and who
do not have negative feelings concerning performance learn and perform better. In
order to promote conceptual change of misconceptions, it is important for teachers to
pay careful attention to the social and affective aspects of students.
Finally, it is important to consider how these theoretical models of conceptual change
can be used to accelerate conceptual change in the classroom. Conceptual change
teaching strategies are exceptionally time-consuming. Hence, the curriculum should
cover fewer topics, allowing teachers and students to investigate concepts in greater
depth and to co-construct a richer understanding (Beeth & Hewson, 1999; Shymansky
et al., 1997; Vosniadou & Ioannides, 1998). Also, since various concepts are related to
one another, curricula should follow a carefully planned sequence of topics in order to
promote understanding (Vosniadou & Ioannides, 1998). Mintzes et al. (1998) and
Vosniadou and Ioannides (1998) also argue that since conceptual change is complex
and involves the co-construction of new knowledge, teachers should promote
interaction among teachers and students, group discussions and verbal expression of
25
ideas. Although most conceptual change research is of an applied nature, the teaching
strategies developed by research are very different from routine teaching and are
seldom used outside of a research program. Duit and Treagust (2003, p.684) argue that
“what works in special arrangements does not necessarily work in everyday practice”
and that it is vital for future research to describe conceptual change strategies in such a
way that teachers can make it part of routine teaching. Millar, as cited by Scott et al.
(2007), also warns that there may be no straightforward, direct correlation between
learning theories and teaching approaches. Hence, teachers are advised to use
activities which investigate the understanding of students and which can then be used in
order to inform later teaching. In addition, researchers are advised to close the gap
between research and practise by engaging with the professional knowledge of
teachers in an attempt to develop guidelines for instructional design (Scott et al., 2007).
2.4.4 Classification of explanation-types
Before I commence my discussion on the classification of explanation-types, it is
important that I explain why I will be using an explanation classification framework to
classify misconceptions. Classifying an explanation assists one in understanding the
characteristics of the explanation and enables one to identify the misconceptions in the
explanation. Also, as previously mentioned, “Explanations are demonstrations of
understanding and provide a window to a person’s thinking” (Zuzovsky & Tamir, 1999,
p.1101). Thus, one can use a classification of student explanations to classify student
misconceptions. Just as there are a range of explanation-types, there are a range of
classification systems for explanation-types. These include Treagust and Harrison’s
(2000) framework and those frameworks which I will discuss in this section –Dagher
and Cossman (1992), Martin (1972) and Gilbert et al. (1998a). I will start by discussing
the Dagher and Cossman (1992) classification framework which I used in my study.
Therafter I will compare their classification framework to classification frameworks
created by two other researchers. Finally I will justify my choice of Dagher and
Cossman’s framework for my study on misconceptions.
26
Dagher and Cossman devised their explanation framework in order to classify verbal
teacher explanations. There are sufficient similarities between teacher and student
explanations. For example, they both aim to provide an answer to a question together
with reasons for the answer, and they both represent the understanding of the person
constructing the explanation. Teacher explanations also influence the construction of
student explanations as previously discussed, hence student explanations may
resemble teacher explanations. Moore and Harrison (2004) used the Dagher and
Cossman explanation framework to effectively analyse written student explanations in
their research study on the use of reflective student explanations to enhance conceptual
learning. Hence, the Dagher and Cossman framework will be appropriate in the
classification of the written student explanations in this study.
The Dagher and Cossman (1992) explanation framework identifies the following ten
explanation-types: tautological, practical, metaphysical, anthropomorphic, analogical,
mechanical, functional, teleological, rational and genetic. In order to enable the
classification of explanations, Dagher and Cossman formulated descriptions of each
type and an organising scheme indicating the relationship between the various types of
explanations. Dagher and Cossman’s organising scheme is included as figure 2.1:
27
Figure 2.1: Dagher and Cossman’s organising scheme for explanations
Source: Dagher and Cossman (1992, p.369)
According to the organising scheme, teacher explanations can be classified as either
theoretical or atheoretical. Dagher and Cossman identified two types of atheoretical
explanations, namely tautological and practical explanations. Gilbert et al. (1998a) refer
to atheoretical explanations as “non-explanations” in their explanation framework and
attribute them to a lack of content-knowledge. Dagher and Cossman described
tautological and practical explanations as follows:
Tautological explanations answer a question by reconstructing the question, and do so
without including any new information, e.g. “Chromosomes are in pairs so that they can
pair” (Dagher & Cossman, 1992, p.366) and “it floats because it is made to float” (Moore
28
& Harrison, 2004, p.7). On analysis of student exam scripts I found tautological
explanations such as “Q, because it is a good conductor” as a response to the question:
“Which one (P or Q) is the better conductor? Explain your answer.”
Practical explanations describe how to do something. For example: “to float you need
to do …” (Moore & Harrison, 2004, p.7) and "The cut of switch is important because
when the multi-plug is over loaded switch on the cut-off switch quick", extracted from my
research data.
Rescher, as cited by Dagher and Cossman (1992, p.368), explains that theoretical
explanations are different from atheoretical explanations because an individual who
constructs a theoretical explanation “rationalizes facts and renders them intelligible.”
Theoretical explanations are divided into two categories on Dagher and Cossman’s
organising scheme, namely spurious and genuine. Spurious explanations or
“counterfeit” explanations (Gilbert et al., 1998b, p.191) are formulated in such a manner
that they cannot be proven as true or false, as opposed to genuine or authentic
explanations which are falsifiable (Trusted, cited by Dagher & Cossman, 1992). Gilbert
et al. (1998b, p.191) warn that spurious explanations may be seen as “legitimate in
certain cultural contexts.” Dagher and Cossman identified two spurious explanation-
types: metaphysical and anthropomorphic; and six genuine explanation-types, namely:
analogical, mechanical, functional, teleological, rational and genetic.
Metaphysical explanations make use of a supernatural agent as the cause, e.g., “God
made it float” (Moore & Harrison, 2004, p.7).
Anthropomorphic explanations allocate human characteristics to a non-human agent
in order to make it more familiar. For example: “she floats because she is lighter”
(Moore & Harrison, 2004, p.7). In my research data I found anthropomorphic
explanations such as "so that electrons would get time to rest when switch it on they
perform a good work.” Treagust and Harrison (2000, p.1165) view anthropomorphic
explanations as “effective pedagogical content explanations, because teachers’
29
pedagogical content knowledge is neither pure science nor is it intended to be.” They
argue that anthropomorphic explanations are used by many teachers, instead of
scientific terminology, to help students understand Physical Sciences.
Analogical explanations make use of a familiar situation to explain a similar but
unfamiliar event, for example: “it can float because it’s like a submarine” (Moore &
Harrison, 2004, p.7).
Mechanical explanations cite causal agents of a physical nature, e.g., “it floats because
of its shape” (Moore & Harrison, 2004, p.7) and an example from my research data: “the
driver of the truck will take less impact because of its size and mass.”
Functional explanations explain events in terms of their immediate consequence or
function (Dagher & Cossman, 1992). Zuzovsky and Tamir (1999, p.1103) explain that a
functional explanation “seeks to understand a behaviour pattern or property by
determining the role it plays in keeping a given system in proper working order.”
Examples of functional explanations include the following: “It floats because of the air in
it” (Moore & Harrison, 2004, p.7), “But we don’t get sick all the time because we have
immune systems that can fight them off” (Dagher & Cossman, 1992, p.364), and “the
current would increase because the resistor like slows down the current and so if it’s not
there it would like increase the current” — an example from my research data.
Teleological explanations explain events in terms of how their immediate consequence
or function contributes, through determined action with other events that are part of the
same physical system, toward the probable attainment of an ultimate consequence,
(Dagher & Cossman, 1992, p.366). Moore and Harrison (2004, p.7) provide the
following example of a teleological explanation: “boats float because we need them to
float.” The following teleological explanation is an example from this study: “the
momentum will not be conserved because the collision may be inelastic."
30
Genetic explanations describe what happens, by relating a sequence of events, and not
why something happens, e.g., “it floated on top of the water” (Moore & Harrison, 2004,
p.7), and “The linear momentum isn’t conserved when both cars move forward after the
collision and the one car moves even further forward”, extracted from my research data.
Rational explanations provide evidence for a claim, e.g., “a boat floats because the up-
thrust from the water equals the weight” (Moore & Harrison, 2004, p.7) and “Therefore
the more the mass of a car, the more the force it will apply on the lighter vehicle
because F α m", extracted from my research data.
The above ten explanation-types generated by Dagher and Cossman were
comprehensive enough to described all of the teacher explanations transcribed in
Dagher and Cossman’s study. However, Gilbert et al. (1998b) argue that Dagher and
Cossman’s framework neglects certain explanation-types which more comprehensively
represent what can be accomplished by Physical Sciences. Gilbert et al. (1998a)
derived their typology of explanations from the relationships between the nature of
questions asked and the explanations which they bring forth. They identified the
following questions asked in scientific investigations and the corresponding explanation-
types:
• Why is the inquiry to be carried out? This question produces an intentional
explanation.
• How does the phenomenon behave? This question produces a descriptive
explanation.
• Of what is the phenomenon composed? This question produces an interpretive
explanation which labels the units within the phenomenon.
• Why does the phenomenon behave as it does? This question produces a causal
explanation.
• How might it behave under other conditions? This question produces a
predictive explanation.
31
In a comparison between their typology and Dagher and Cossman’s typology, Gilbert et
al. explained that their descriptive and interpretive explanations might be seen as being
rational and analogical explanations respectively. They also grouped mechanical,
teleological, functional and genetic explanations together as being part of their causal
explanations, because they just link an action and a reaction. They did, however, argue
that this group of causal explanations represented “weak forms of causal explanation
because they contain no statement about a mechanism which links action and reaction”
(Gilbert et al., 1998b, p.191).
According to Gilbert et al. (1998a, p.87) their typology of explanations corresponds
agreeably with another explanation typology by Martin (1972), which was derived by
focusing on the activity of providing an explanation and the discourse involved in doing
so. I have summarised Gilbert et al.’s comparison in the table 2.1:
32
Table 2.1: Comparisons between various authors’ explanation-types
Ty
pe
s o
f e
xp
lan
ati
on
s
Martin Gilbert et al. Dagher and Cossman
Justification (Provision of reasons
why a belief or action is reasonable)
Intentional
Clarification (Description of how
phase relates to phenomenon)
Descriptive (Clarification of meaning)
Rational (Evidence is provided for a claim)
Gen
uin
e
Th
eo
retica
l
Citation of theory Interpretive Analogical
(Unfamiliar is described in terms of familiar)
Causal account (Propositional
statement stating why something is)
Causal
Genetic (A sequence of events are related)
Mechanical (Physical causal relationships are
given)
Functional (A phenomenon is explained in terms of
its immediate consequence)
Teleological (A phenomenon is explained in terms of
how its immediate consequence contribute towards an ultimate
consequence) Predictive
(Deduction of future events)
Attribution of function (Not based on a
question as in Gilbert’s typology)
Metaphysical (A supernatural causal agent is given)
Sp
uri
ou
s
(Fa
lse
)
Th
eo
retical
Anthropomorphic (Human characteristics are attributed to
a non-human agent)
Non-
explanation
Practical (Instructions as to how to perform
operations)
Ath
eo
retica
l
Tautological (The question is reformulated)
Source: Compiled by researcher
33
Dagher and Cossman’s framework of explanation-types is better suited to this study
because, firstly, it has been used to analyse written student explanations and detect
misconceptions (Moore & Harrison, 2004). Secondly, it makes a greater distinction
between the various types of explanations, thereby identifying explanation-types which
are excluded by other frameworks. For example, it differentiates between the different
causal explanations, those of mechanical, teleological, functional and genetic
explanations. This distinction is useful in my study on misconceptions as it reveals the
different incorrect and/or incomplete causes which students use to clarify why
something happens. Thirdly, this study involves the analysis of explanations produced
from exam questions which required only causal and descriptive type explanations. The
following questions are the exam questions, related to my study, which required causal
explanations:
• Explain why the conservation of linear momentum may NOT be valid in this
collision.
• Use principles of Physics to explain why the risk of injury for passengers in a
heavier car would be less than for passengers in a lighter car.
• Is plate B negatively or positively charged? Give a reason for your answer.
• Which one (P or Q) is the better conductor? Explain your answer.
• Using principles in Physics, explain why this cut-off switch is important.
The following are the questions that required descriptive explanations:
• Explain what happens to the 15% of the kinetic energy that is NOT converted into
electrical energy.
• Briefly describe the diffraction pattern that will be observed on the screen.
• Name ONE similarity and ONE difference in the pattern observed when the
single slit is replaced with a double slit.
• What type of generator is illustrated in the diagram? Give a reason for your
answer.
The following exam questions appear to be predictive, but since they all involve
predictions that are covered in exemplar-type questions found in textbooks they are
actually causal:
34
• Will this pattern be observed if the laser is replaced with a light bulb? Give a
reason for your answer.
• How will the reading on voltmeter V change if resistor R burns out? Give a
reason for your answer.
• State and explain what effect this increase in the intensity of incident radiation
has on the energy and number of emitted photo-electrons.
Therefore, including the intentional and predictive explanations from Gilbert et al.’s
framework would be unnecessary.
2.5 LITERATURE REVIEW
In this next section I will review studies regarding the complex nature of misconceptions
and the sources of these misconceptions. I will discuss research on the relationships
between misconceptions and language, misconceptions and assessment and
misconceptions and context. I will consider common misconceptions in the field of
Physics, as well as contemporary teaching strategies designed to aid in the
identification and remediation of misconceptions.
2.5.1 The nature of misconceptions
In section 2.3.2 I briefly discussed the differing perspectives regarding the status of
misconceptions. In this section I will continue this discussion and also discuss the other
dimensions of the multifaceted nature of misconceptions.
On the one hand misconceptions were traditionally viewed as incorrect ideas which
“conflict with accepted scientific explanations” (Mintzes et al., 1998, p.75).
Misconceptions were viewed as “barriers and misleading elements in thinking”
(Tytler, 1998, p.909), which obstruct the conceptual understanding of students
(Chittasirinuwat, Kruatong & Paosawatyanyong, 2009). Palmer (2001, p.194) explains
that misconceptions “interfere with learning” and Posner et al., (1982) argue that
misconceptions need to be replaced. Traditional studies also reported that
misconceptions are extremely persistent and resistant to change (Clough & Driver,
35
1986; Eggen & Kauchak, 2004; Driver, Guesne & Tiberghien, 1985; Mintzes &
Wandersee, 1998; Pine et al., 2001; Posner et al., 1982; Tytler, 1998), which makes
removing them problematic.
On the other hand contemporary studies argue that while misconceptions may be
different to expert scientific conceptions, they are useful preconceptions which are
still under construction, constantly evolving and thereby enabling learning (Novak,
2004; Smith et al., 1993). Misconceptions are useful as explanations of everyday
experience (Mintzes et al., 1998; Vosniadou & Ioannides, 1998). However, they are not
only useful in everyday life but also act as “useful recognition pathways into higher
order conceptions” (Tytler, 1998, p.909) or as “anchoring conceptions” (Clement et al.,
1989, p.554).
I have illustrated these opposing perspectives in figure 2.2:
Figure 2.2: The nature of misconceptions –stumbling blocks or stepping stones
Source: Compiled by researcher
As I have mentioned in section 2.3.2, I view misconceptions as useful prior knowledge
which act as stepping stones that enable students to construct a deeper understanding.
Persistent
Useful preconceptions
Conflicts with
science
Useful recognition
pathway
Enables learning Interferes with
learning
Barrier in thinking
Evolving
Incorrect ideas
Different to scientific
conceptions
Need to be recrafted (Under construction)
Need to be replaced
36
I will proceed by discussing the other characteristics of misconceptions. Misconceptions
co-exist with more advanced scientific conceptions (Alzate & Puig, 2007; Palmer,
2001; Scott et al., 2007). Viennot as quoted by Tytler (1998, p.923) explains that
intuitive and scientific conceptions co-exist even in the minds of scientists and that an
intuitive conception “reappears in the expert when he or she lacks time to reflect.” Smith
et al. (1993, p.124) also explain that “students can shift between correct and flawed
approaches within the same problem-solving episode, which suggests that cognitive
structures can embrace both expert concepts and misconceptions.” Tytler (1998, p.923)
warns that:
The existence of naive alongside more sophisticated, generalizable conceptions, should not be
seen merely in terms of the inability to apply the higher order conception in particular situations
(although this can be true, and leads to a falling back to the more naive conception), but should
be viewed in terms of these more naive conceptions forming part of a network of supportive
intuitive ideas which serve a useful function as phenomenological markers, or scaffolds.
Students may also have concurrent multiple conceptions within any one subject area
(Hamza & Wickman, 2009; Palmer, 2001). These multiple misconceptions often
depend on the context of the problem (Moore & Harrison, 2004; Tytler, 1998), hence
a particular problem context would activate a particular alternative conception and
another context would activate another alternative conception, resulting in an apparent
incoherence of the student’s response (Clough & Driver, 1986; Driver et al., 1985;
Palmer, 2001). Also, because students often make sense of their observations and
experiences in terms of their preconceptions, these preconceptions are steeped in
everyday language (Tytler, 1998).
Often scientists, teachers and students share similar intuitive conceptions as
misconceptions are shared amongst a diversity of cultures, ages, abilities,
genders, subjects and levels of experience (Alzate & Puig, 2007; Driver et al., 1985;
Mintzes, et al., 1998; Scott et al., 2007; Vosniadou & Ioannides, 1998). Intuitive
knowledge is also internally logical to the student as it is based on reasoning by the
student and observations made by the student (Driver et al., 1985; Mintzes, et al.,
37
1998). Intuitive knowledge is often hidden from both students and teachers (Mintzes et
al., 1998; Smith et al., 1993; Thompson & Logue, 2006). Students are often unaware of
the explanatory frameworks they have constructed (Vosniadou & Ioannides, 1998), and
are rarely asked to explain their thinking in class. Even when exams are designed to
probe conceptual understanding and an explanation is required, students are restricted
by short time limits and other pressures inherent in examinations and may not reveal
their misconceptions.
2.5.2 Sources of misconceptions
Without a proper understanding of how and why students come to think in the ways that
they do, “teachers have a very limited basis for planning teaching that can support
conceptual change” (Franco & Taber, 2009, p.1946). Hence, I will continue this review
of literature by investigating the sources of student misconceptions. I will commence this
review by discussing the origins of misconceptions that are internal with regard to the
student, then I will discuss external origins of misconceptions that involve various social
role-players and finally I will discuss external origins that involve tools of learning.
Since misconceptions are constructed by an individual, the individual is the primary
source of misconceptions. Driver et al. (1985) explain that students internalise their
experience in a personal manner. This is because observation, experience and
understanding are influenced by an individual’s prior beliefs and knowledge (Carr et al.,
1994; Strike, 1983). In other words, experience and observations do not cause
misconceptions; rather misconceptions cause an individual to experience and observe
reality in a manner which differs from reality. Consequently, an individual’s incorrect
interpretation of experience and observations either reinforces the initial
misconception or is used by the individual to construct a new misconception. Also, when
students apply concepts to situations where they do not apply; such over-
generalisations also constitute misconceptions (Smith et al., 1993). Pine et al. (2001)
explain that overgeneralisations are not easily abandoned because they work in certain
situations.
38
Children also ask family members, acquaintances and other members of society
about how and why things happen (Kibuka-Sebitosi, 2007, p.57). Many of these socially
constructed theories are different to the scientific theories that they learn in the Physical
Sciences class and since these alternative conceptions work in the context of the
student’s observations, students are hesitant to accept scientific concepts.
Alternative ideas or misconceptions also arise in the classroom as a result of the
interaction between students and their peers and their teachers. Students co-
construct conceptions together with the various role-players found in the classroom, by
adding onto and restructuring their pre-concepts according to the new concepts that are
introduced. Often, these constructs are incorrect or partially incorrect. During classroom
interactions students may also be presented with incorrect conceptions by peers or
even teachers (Kikas, 2004), which they then make their own. In fact, studies have
shown that teachers hold various misconceptions on topics they teach in school
(Bayraktar, 2009; Kikas, 2004).
Teachers make use of a variety of learning tools in an attempt to enrich learning; often
these tools are a source of misconceptions. For example, teachers and textbook writers
use analogies to illustrate a concept. Thiele and Treagust (1991, p.2) explain that an
“analogy can allow new material to be more easily assimilated with the students’ prior
knowledge enabling those who do not readily think in abstract terms to develop an
understanding of the concept.” However, the use of analogies in facilitating students
understanding of complex concepts has also been problematic, as the differences in the
attributes between analog and target are often a cause of misunderstanding for
students when they map unshared attributes from the analog to target (Dilber &
Duzgun, 2008; Orgill & Bodner, 2004). Also, students sometimes take these analogies
too far and are unable to separate them from the original subject content; other students
only remember the analogy and struggle to remember the original content (Thiele et al.,
1995).
39
Furthermore, the curriculum expects students to apply scientific theories to real world
problems, but a gap exists between the complexity of the real world and the
sparseness of scientific theory (Smith et al., 1993), so this leads to the formation of
misconceptions. Real world problems rarely adhere to the conditions under which
scientific theory exists; this confuses the students. Pallrand (1996, p.317) explains that
“Scientific knowledge in school often appears in a form that is abstract, formal, and
decontextualized. As a result it may be difficult to relate new knowledge to what is
already known.”
Studies on the analysis of textbooks have reported the occurrence of high levels of
misconceptions within textbooks (Hubisz, 2003; King, 2010; Stefani & Tsaparlis, 2009).
Also, the language used in textbooks and in classrooms may be another source of
misconceptions. According to Gunstone and Watts (1985. p.101) “Language which is
meaningful to teachers may, because of students’ views of the world, have a quite
different (even conflicting) meaning for students.” In other words, the incorrect use and
interpretation of language may be the source of misconceptions. Strike (1983, p.22)
argues that “We may often have little further to look for the sources of misconceptions
than how we talk.” I will discuss the effect of language on concept formation in more
detail in the next section.
It may not be possible or even necessary to eliminate these sources of misconceptions,
as misconceptions form the framework upon which conceptual restructuring takes
place. However, it remains important that teachers and students become aware of these
sources of misconceptions and, where possible, avoid reinforcing incorrect conceptions.
2.5.3 The relationship between language and misconceptions
The relationship between language and misconceptions is complex. Firstly, language
can expose misconceptions. According to Moore and Harrison (2004) when students
use different scientific terms interchangeably as if they have the same meaning, their
incomplete understanding is exposed. Secondly, when students label concepts
incorrectly because they do not have the required vocabulary to express themselves,
40
language problems can be misdiagnosed as misconceptions (Clerk & Rutherford,
2000; Kibuka-Sebitosi, 2007; Schuster, 1983). Thirdly, the incorrect use and
misinterpretation of language can cause misconceptions. I will continue this
discussion by discussing how the incorrect use and misinterpretation of language
causes misconceptions.
The incorrect use of scientific language by teachers, family, friends, the authors of
textbooks and the media can cause misconceptions, because from a social
constructivist perspective students co-construct their understanding together with these
various social role-players (Duit & Haeussler, 1994; Kikas, 2004).
The nature of scientific language is complex and abstract, making it difficult for students
to link new scientific language to existing conceptions and to construct new conceptions
without possibly constructing misconceptions. Jones and Carter (1998, p.265) explain
that students who do not understand this scientific language “fail to develop viable
concepts.” Also, understanding the language of Physical Sciences involves more than
understanding separate concepts, it involves understanding the relationship between
concepts and the language used to represent those relationships. Mastering the
scientific language is even more complex when one considers the multimodal nature of
the language of Physical Sciences. The language of Science is a combination of
“words, diagrams, pictures, graphs, maps, equations, tables, charts, and other forms of
visual and mathematical expression” (Lemke, as cited by Scott et al., 2007, p.47).
Hence, students are required to understand not only the abstract terms and
relationships between them but they must also be able to move comfortably between
graphs, mathematical relationships and the language used in scientific investigations.
Students who are required to study Physical Sciences in their second language, such
as the majority of students in this study, may struggle even more to understand abstract
scientific language as they generally have a poor command of the ordinary English that
is used to explain scientific concepts (Kibuka-Sebitosi, 2007).
41
When students do not realise the differences between the everyday and scientific use of
the words, they may construct misconceptions. White (1994) argues that
misconceptions are more prevalent for topics that make use of ordinary words in an
expert manner. Learning a new scientific meaning of an ordinary word requires students
to connect their existing everyday social language meaning to a new scientific meaning
and to change their understanding if necessary (Bryce & MacMillan, 2009). Physical
Sciences language also differs from everyday language with regard to the manner in
which reality is viewed. Physical Sciences and everyday language sometimes place the
same concept into different ontological categories (Scott et al., 2007). Students who are
unaware of these differences may hold a misconception. For example, the concept of
weight is categorised as a property of matter in everyday language and as an
interaction in Physical Sciences language.
The differences between written and spoken language also influences the formation of
misconceptions. Carlsen (2007) clarifies that talk is social whereas writing is personal.
Hence, it is important for students to practise writing explanations as a way of moving
from the social to the personal plane in order to internalise new concepts. The practise
of writing actually forms part of the process of conceptualisation, rather than a mere
transfer of knowledge. Hence, it is understandable that students with a lack of
experience in writing explanations will yield incomplete concepts. The importance of
writing activities is discussed in further detail in a following section.
2.5.4 The relationship between assessment and misconceptions
Assessment affects why, what, and how we learn; and learning, in turn, affects the
development of assessment methods and assessment results. Mintzes, Wandersee and
Novak (2001, p.123) are confident that “the way we choose to evaluate and reward
student work may be the single most significant determinant of high quality conceptual
understanding.” I will commence by discussing how assessment may negatively affect
the development of student conceptions. I will continue by discussing how assessment
can positively affect learning through the diagnoses of misconceptions and through the
remediation of misconceptions.
42
Traditionally the focus of assessment has been on testing whether a candidate has the
knowledge needed to gain entrance to the next grade, level, course or job. Hence,
traditional assessment is largely summative, occurring after teaching (Klassen, 2006;
Treagust, Jacobowitz, Gallagher & Parker, 2001). The information on student
conceptions that is gained from traditional summative assessment is used to grade the
student. Unfortunately, traditional summative assessment is not used to design
teaching strategies which could remediate misconceptions and develop
conceptual understanding.
Critique of traditional assessment also highlights the argument that traditional
assessment discourages the development of student conceptual frameworks by
over-emphasising the rote learning of facts and the solving of exemplar-type
problems. This over-emphasis “allows students to get by with rote learning” (Morrison
& Lederman, 2003, p.863) and takes the teaching focus away from the development of
deeper understanding and conceptual change, which in turn means students do not get
to develop their incomplete conceptions (Akku et al., 2003; Driver et al., 1985). Bryce
and MacMillan (2009, p.739) explain that “The commonly emphasized mechanistic,
number-crunching approach to the analysis of simple collision problems is judged to be
un-profitable” and “may be the source of many misunderstandings.” Halloun (1998,
p.239) adds that Physical Sciences students “often pass their courses without
meaningful understanding of the subject matter” and Harrison, Grayson and Treagust,
(1999, p.55) confirm that “Some high-achieving students complete physics courses with
many of their intuitive conceptions intact.” Without the pressure of having to teach to the
test, students and teachers will be able to engage in meaningful learning and even
meaningful assessment. Mintzes et al. (2001, p.118) remind us that “The way we
choose to assess student progress conveys much about what we value, and these
values are readily discerned, internalised, and acted upon by students. ...If our goal is to
encourage understanding we must make that goal clear to our students by our choice of
assessment strategies.”
43
Another problematic issue regarding traditional assessment is that traditional
assessment fragments and decontextualises knowledge. This causes students to
struggle with connecting new information to their existing conceptual framework, and
with constructing integrated cohesive knowledge frameworks that can be readily
accessed and used. Mintzes et al. (2001, p.118) warn that “we live in a strongly
interconnected world, and students will need to leave school with more than just bits
and pieces of disconnected knowledge.” Besides, Halloun (1998, p.247) adds that “An
isolated concept is practically meaningless and useless.” Furthermore, Klassen (2006,
p.832) explains that “Testing for a particular piece of knowledge in a decontextualized
manner will not tell the assessor to what degree this knowledge has been integrated
with long-term memory structures.” Nor will decontextualised and fragmented
assessment reveal misconceptions that co-exist alongside scientific conceptions, so
that they can be addressed.
The stress caused by traditional summative assessment forms part of the social
and affective variables that may negatively affect conceptual change. Klassen
(2006, p.844) clarifies that “high-stakes assessment tends to produce elevated stress
levels for teachers and students and decreased student motivation.” Students who are
stressed and unmotivated have difficulty concentrating on the construction of new
scientific concepts when their thoughts are preoccupied with fears. So they may not
make the necessary links between the new knowledge and their pre-knowledge,
resulting in incomplete conceptions or misconceptions. According to Palmer (2005)
stress may also affect the remediation of misconceptions, because the reconstruction
of misconceptions involves focussed linking of new knowledge to pre-
knowledge, and distracted students may lack the motivation to make the effort
required. Zusho et al., (2003, p.1083) explain that “worry and negative emotions about
doing well in class, has been found to have negative consequences on cognition.”
Therefore Palmer (2005) advises that concepts linked with misconceptions should not
be presented to students until they have developed a conceptual framework that will
enable them to achieve reconstruction of a misconception within a few minutes of effort.
44
Traditional assessment in Physical Sciences education consists predominantly of
methods such as “selected-response” questions like multiple choice questions, brief
“constructed-responses” and exemplar-type questions (Klassen, 2006). Mintzes et al.
(2001) warn that such 20th century methods of assessment do not effectively reveal a
student’s true level of understanding. Hence, traditional assessment often does not
expose alternative conceptions. Multiple-choice questions have been used to
diagnose misconceptions in research studies (Akku et al., 2003; Schmidt, 1997;
Tekkaya, 2003), but in these studies the distracters were chosen from previous
research on student misconceptions. So it is possible to also use multiple-choice
questions in school assessment for the purpose of diagnosing misconceptions if the
distracters target student misconceptions. Furthermore, Schmidt (1997) argues that the
use of multiple-choice tests by Physical Sciences teachers for the purpose of
diagnosing misconceptions is less time-consuming than alternative methods such as
student interviews. Clerk and Rutherford (2000), however, warn that multiple-choice
questions may not be the best method of diagnosing misconceptions because one
cannot assume that students hold a specific misconception just because they choose
the corresponding distracter. Shaw, Bunch and Geaney (2010) explain that the
students’ language proficiency affects how they answer multiple-choice assessments.
Hence, language problems may be misdiagnosed as misconceptions (Clerk &
Rutherford, 2000). In addition, whether or not traditional assessment successfully
uncovers alternative conceptions, it does not promote effective feedback regarding
students’ individual conceptions. Teachers generally only discuss the correct answer
and have little time to discuss either the distracters in a multiple-choice assessment or
alternative ideas in another form of assessment.
Despite the critique against traditional or summative assessment, it remains established
as the most popular form of assessment, because schools are subject to high stakes
external final exams of a summative nature. Hence, it continues to have a negative
effect on meaningful learning.
45
I will continue by discussing how assessment can positively affect learning. Baseline
and diagnostic assessment can be used to diagnose alternative student
conceptions. The National Curriculum Statement (NCS) (Department of Education,
2003, p.56) explains that baseline assessment is useful to “establish what students
already know and can do” and that it is helpful in the planning of learning activities; the
NCS also encourages diagnostic assessment in order to “discover the cause or causes
of a learning barrier” and to assist in “deciding on support strategies”. İngeç (2009)
argues that diagnostic assessment methods, such as concept mapping, can provide
information about students’ misconceptions which is not extracted from summative
tests. Baseline and diagnostic assessment can therefore be used by teachers to
uncover misconceptions that students have at the start of a topic and that students
develop as teaching of the topic progresses.
Despite the importance of diagnostic assessment and teachers’ awareness of the
importance of diagnosing student’s preconceptions, Morrison and Lederman (2003)
found that teachers do not use a variety of diagnostic strategies such as pre-tests,
concept maps, interviews, or journals. Also, when teachers do use diagnostic
assessment, they found that teachers usually use only informal verbal assessment or
written summative assessment in order to diagnose whether or not the student knows
the correct answer. It is not common practice to use assessment to diagnose what
misconceptions students hold and to follow up on the diagnosis by addressing the
misconceptions. Morrison and Lederman (2003) propose that the absence of diagnostic
assessment and the necessary follow-up elicited by diagnostic assessment may be as a
result of the pressure placed on teachers to complete a set amount of work in a limited
time frame; teachers may also hold beliefs that do not agree with constructivist
teaching. The implementation of the NCS was accompanied by teacher training on
alternative forms of assessment such as baseline and diagnostic assessment. However,
I argue that the curriculum is too broad and agree with Morrison and Lederman that
teachers do not have enough time to implement effective assessment.
46
Even though baseline and diagnostic assessment is not common practise, it has been
shown to be an effective manner of diagnosing misconceptions. Treagust, Jacobowitz,
Gallagher and Parker (2001) report that Gallagher, a teacher, effectively used a written
pre-test consisting of open-ended questions as well as a diagnostic question at the start
of each lesson, oral feedback and embedded written activities in order to assist her in
identifying alternative student conceptions.
Assessment can be used, not only to diagnose misconceptions, but also to assist
students in reconstructing their conceptions so that they become scientifically
acceptable. When assessment is used to assist students in the construction of
knowledge, in other words “assessment for learning and not of learning” (Furtak & Ruiz-
Primo, 2008, p.800), it is known as formative assessment. According to Black and
William, as cited by Furtak and Ruiz-Primo (2008, p.800), formative assessments are
“all those activities undertaken by teachers, and/or by their students, which provide
information to be used as feedback to modify the teaching and learning activities in
which they are engaged.” Formative assessment “monitors and supports the learning
process” (Department of Education, 2003, p.56).
Treagust et al. (2001, p.155) promote the use of formative assessments such as writing
tasks, performance tasks and portfolio-based assessment, because it gives students
“the opportunity to express their understanding and reconcile their personal ideas with
scientifically accepted ideas.” Mintzes et al., (2001) add that the use of concept maps,
written and oral reports and collaborative assessment strategies also support the co-
construction of knowledge in small groups and the reconstruction of individual
misconceptions. The use of a variety of formative assessment strategies by
teachers increases the opportunities they have to attend to students’ conceptions
(Furtak & Ruiz-Primo, 2008).
Shaw et al., (2010) do, however, warn that since formative assessments require
students to express their ideas in greater detail, they may generate additional linguistic
challenges for students. However, formative assessment may be seen as an
47
opportunity to develop students’ linguistic ability (Hein, 1999). Treagust et al., (2001)
argue that formative assessments should also not require only very short answers from
students, as short answers do not encourage in-depth thinking. Hence, training teachers
in the formulation of assessments which use open-ended clarifying questions, questions
that expose the students’ understanding, is vital. It is also important not to distort the
purpose of formative assessment by using it to assess the performance of students and
for promoting students to the next grade. Klassen (2006) reminds us that there is not
enough evidence to guarantee the reliability and validity of formative methods for that
purpose. Since teachers, and sometimes peers, co-construct the formative assessment
product in the form of an essay, presentation or concept map, it may not reliably
represent the individual student’s understanding. Therefore, summative assessment
should be used to measure the performance of students as it aims to assess learning
(Department of Education, 2003).
Many new forms of assessment have been introduced, each posing new challenges.
Nevertheless, since assessment remains one of the most important tools for revealing
and remediating student misconceptions, it is vital that we continue to reflect on how we
use assessment to do just that. The purpose of assessment at schools should become
more diverse so that it includes tasks which expose and address misconceptions.
2.5.5 The relationship between context and misconceptions
Context refers to the unique setting or situation of an event (Clough & Driver, 1986). I
will commence this discussion by discussing how the relationship between
misconceptions and contexts may be problematic. Next I will discuss how contexts can
form part of the solution to re-crafting misconceptions.
According to Strike (1983), misconceptions are not formed as a result of students’
observations and experiences; rather it is students’ observations and experiences that
are formed by their misconceptions. Hills (1983) emphasises that “observation is theory-
laden.” In other words, students see what they expect to see. Also, students use their
misconceptions to make sense of what they observe and experience in everyday-life
48
situations (Carr et al., 1994). Therefore, misconceptions are seen to apply to
everyday-life contexts.
Strike (1983) explains that misconceptions can actually be valid and functional within
some contexts. It is when misconceptions are extended beyond their productive range
of application that they lead to erroneous conclusions. In other words, misconceptions
have a limited “context of application” (Smith et al., 1993, p.148).
When scientific knowledge does not match students’ misconceptions, students may
create a separate context of application for scientific knowledge, in order to assimilate it.
This separate context of application is usually the situation sketched in exemplar-type
questions used in Physical Sciences classrooms. Gunstone & Watts (1985, p.88)
explain that “It is not uncommon for students to learn the physicists’ perspective and
apply it to identifiably ‘physics-type’ situations, while still interpreting the real world in
other ways.” In other words, scientific knowledge is seen, by students holding
misconceptions, to apply only to the classroom context. As a result,
misconceptions and scientific knowledge co-exist within students’ conceptual
frameworks, each within their own separate context (Klassen, 2006; Tytler, 1998).
The co-existence of misconceptions and scientific knowledge within students’
conceptual frameworks is problematic. Firstly, the new scientific knowledge is only
loosely added on to the student’s conceptual framework and is seen to have a limited
context of application. Secondly, the misconception has a limited context of application.
Thirdly, when students are expected to apply Physical Sciences to an everyday-life
situation, the everyday-life context cues the use of misconceptions and everyday
social language (Duit & Haeussler, 1994; Tytler, 1998). Also, since contemporary
assessments promote the application of knowledge, everyday-life contextual cues are
common. Another dimension of this problem is that sometimes students are unfamiliar
with the everyday-life context used in assessments. If the student has never
experienced the real-life context used in assessment or teaching, then the student will
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struggle to make the connection between the context of application and the scientific
concept under assessment.
The solution, however, is not to terminate the use of everyday-life contextual questions.
Instead teachers need to be aware of these contextual cues and need to focus on
enabling conceptual change. Conceptual change involves re-crafting the
misconception so that it represents the scientific knowledge, thereby broadening
its contextual domain of application (Halloun, 1998). Dekkers and Thijs (1998, p.49)
describe this as “context expansion”, when the context of application of scientific
concepts is extended from the classroom context to the practical context. Palmer (1997)
recommends exposing students to a range of qualitative problems with a variety of
different contextual features in order to expand the student’s range of application.
Another important dimension of the remediation of misconceptions is the classroom
context, or learning environment. Since conceptual change of misconceptions is more
than a cognitive activity, and is influenced by motivational and affective factors such as
discussed in section 2.4.3, the classroom context should support knowledge
refinement and the re-crafting of misconceptions (Smith et al., 1993). In order to
support the refinement and re-crafting of misconceptions, the classroom context must
allow children the freedom to express their ideas without fear of being ridiculed.
2.5.6 Misconceptions within the field of Physics
In this section I will review research studies that have identified common student
misconceptions. In this review I will focus in particular on studies related to Physics
topics that are addressed in the South African Physical Sciences curriculum.
2.5.6.1 Misconceptions regarding Newton’s Laws on Motion
Possibly the most well researched topic in the field of misconceptions is that of
mechanics (Clough & Driver, 1986; Mintzes et al., 1998). Research has shown that
misconceptions on force are very resistant to change (Gunstone & Watts, 1985;
Halloun, 1998). I will continue by discussing cases of misconceptions regarding force.
50
One common misconception is that force is a “primary quality of an object” (Galili in
Moore & Harrison, 2004, p.3) as opposed to an interaction between objects
(Shymansky et al., 1997). This misconception has been described as similar to
medieval impetus theory which attributes motion to an internal source of force or
impetus (Bayraktar, 2009; Gunstone & Watts, 1985). Students holding this
misconception ascribe the incorrect ontological category to force, and see it as a
property of matter, much like mass, instead of seeing it as an interaction between two
objects.
A second common misconception is that “Forces are to do with living things.”
Students holding this misconception attribute human characteristics to an inanimate
object and construct anthropomorphic explanations such as an object “trying to fight its
way upwards against the will of gravity” (Gunstone & Watts, 1985, p.91).
A third common misconception that shares the anthropometric view discussed above is
that during the interaction between two objects “the object with greater mass, or the
more active object, exerts greater force” (Bayraktar, 2009, p.275). Students holding
this misconception view the interaction between objects as a struggle where victory
belongs to the stronger, bigger, heavier, or more active object (Eshach, 2010). This
misconception contradicts Newton’s third law and may be a distortion of Newton’s
second law that indicates that heavier objects require a greater force than lighter objects
to experience the same acceleration.
A fourth common misconception, which may originate from the view that forces are to
do with living things, is that static inanimate objects can’t exert forces (Clement et
al., 1989). Clement explains that although students struggle to believe that a book
exerts a force on the table on which it is lying, many students understand that a
compressed spring is able to exert a force. Teachers can use this to explain that all
objects have a degree of elasticity and are able to exert a force. Students holding this
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misconception also struggle to believe that Newton’s third law applies to the interaction
between a table and a book lying on it (Eshach, 2010).
A fifth common misconception is that if a force is applied to an object it moves
(Dekkers & Thijs, 1998). Students may believe this because it is true in the context of
resultant or unbalanced forces. However, it is incorrect in the context of balanced forces
where the resultant force is zero.
Similar to the fifth common misconception is the sixth common misconception that
objects are at rest or are slowing down in the absence of a force (Gunstone &
Watts, 1985; Mintzes et al., 1998). This is not true, as stationary objects imply a zero
resultant force not the absence of all forces, and slowing down requires a resultant
force.
The seventh common misconception that motion requires a force (Bayraktar, 2009;
Clough & Driver, 1986; Shymansky et al., 1997) is also linked to the previous
misconceptions. This is incorrect because an object can move at a constant velocity in a
frictionless system without the presence of a force. Also, it is more specifically
accelerated motion, which requires a resultant force.
An eighth common misconception is that a force applied to an object causes motion
in the direction of the force (Gunstone & Watts, 1985; Mintzes et al., 1998; Palmer,
1997). This conception is true only in the context where a resultant force is applied to a
stationary object. However, motion can be in a direction opposite to that of the applied
force; for example, when a car’s brakes are applied it continues to move forward for a
considerable distance.
A ninth common misconception is that a constant force causes an object to move at
a constant velocity (Bayraktar, 2009; Mintzes et al., 1998). This misconception
contradicts Newton’s second law which states that a resultant force, which could be
constant or irregular, causes acceleration. Constant resultant forces cause constant
52
acceleration and irregular resultant forces cause irregular acceleration. This
misconception is only correct in a context where the constant force is not a resultant
force but rather a balanced force acting on a moving object. An object which
experiences constant applied and frictional forces which are equal in magnitude, in
other words, experiencing a zero resultant force, will move with a constant velocity.
A tenth common misconception is that the rate of motion is proportional to the
magnitude of the force (Mintzes et al., 1998). Students holding this misconception
could either believe that the velocity of an object is proportional to the force or that the
acceleration is proportional to the force. If they believe that the acceleration is
proportional to the force, they are correct if the mass of the object is kept constant and
the force is a resultant force. When comparing the acceleration of objects with equal
masses under the action of a resultant force the rate of acceleration will also be
proportional to the magnitude of the resultant force according to Newton’s second law.
Students who believe that the velocity of an object is proportional to the force, believe
that the slower an object moves the less the force is that is acting on it. This is not
correct, as the velocity of an object does not only depend on the forces acting on it but
also depends on the object’s mass. In addition, the velocity of an object does not only
depend on the applied force acting on it, but also depends on the frictional and braking
forces acting on the object. Objects may move slowly even when a large resultant force
is acting on them, this happens when the large force has only been active for a short
period of time or when the object is very heavy.
An eleventh common misconception is that forces acting on two different objects
can be added (Halloun, 1998). Although it is true that the resultant force acting on each
of two stationary interacting bodies is zero, it is not because the forces they are exerting
on one another add up to zero, but rather because the forces acting on each body
separately add up to zero.
Although the above conceptions are incorrect within certain contexts, they are correct in
others, which is why Dekkers & Thijs (1998, p.41) argue that although these
53
conceptions “need refinement” they “have the potential to become the basis for
development of the physics concept of force.”
2.5.6.2 Misconceptions regarding momentum and kinetic energy
The difficulties associated with teaching and learning momentum and kinetic energy has
been discussed in a number of international studies (Bryce & MacMillan, 2009; Lin,
1983). Students struggle with developing an understanding of the difference between
momentum and kinetic energy, and the conservation of these quantities. Students hold
a variety of alternative conceptions regarding momentum and kinetic energy. I will
continue by discussing the common alternative conceptions held by students regarding
the two quantities of motion: momentum and kinetic energy.
One misconception is that momentum and kinetic energy are the same (Bryce &
MacMillan, 2009; Lin, 1983). One of the students in Lin’s study, on the relationship
between Physics students, the Physics classroom and Physics subject material,
explained that momentum and kinetic energy are the same because “They both
incorporate mass and velocity” (Lin, 1983, p.451). These two quantities of mass in
motion appear to be so similar, that even pioneering physicists found the development
of these two concepts to be a difficult and drawn-out task (Bryce & MacMillan, 2009).
Bryce and MacMillan (2009) add that simply pointing out the differences in the
mathematical formulae and emphasising the practice of plugging numbers into these
formulae do nothing to enhance the understanding of students regarding the difference
between momentum and kinetic energy. They suggest that the differences between
these quantities be dealt with more explicitly by discussing how momentum and kinetic
energy are affected by a change in an object’s motion. Since, the resultant force X time
= change in momentum, while the resultant force x distance = work = change in energy,
doubling the velocity of an object will double its momentum and double the time
required to bring it to rest with the same force; whereas as doubling the velocity of an
object will quadruple the kinetic energy (Ek = 1/2mv2) and quadruple the distance
required to stop the object using the same force (Bryce & MacMillan, 2009). According
to Bryce and MacMillan, it is also important for teachers to emphasise that kinetic
54
energy can be transformed into other forms of energy, whereas momentum cannot be
converted into other forms.
A second common misconception is that kinetic energy is a vector. Students holding
this misconception believe that since “the work done against gravity is ‘real’ and
therefore positive, work done by gravity is ‘negative’” (Bryce & MacMillan, 2009, p.742).
Also, since work done is the change in kinetic energy, students conceive work and
kinetic energy to be directional. Another reason for this intuitive idea is the previously
mentioned difficulty students have in differentiating between kinetic energy and
momentum. Since momentum is a vector, students conceive of kinetic energy as being
a vector. Bryce & MacMillan (2009, p.744) add that “Youngsters familiar with films such
as ‘‘Armageddon’’ are all too aware that the direction of the asteroid approaching the
Earth, bringing with it sufficient energy to annihilate the planet, makes a world of a
difference!”
A third common misconception is that “momentum was conserved for each object in
a system rather than being conserved by the system of objects as a whole” (Bryce &
MacMillan, 2009, p.742). Students holding this misconception do not understand that
momentum is transferred during a collision, thus when they are told that momentum is
conserved and cannot be transformed into something else they may erroneously
assume that each individual object’s momentum is conserved.
A fourth common misconception is that total momentum is not conserved in
collisions with ‘‘immovable’’ objects (Bryce & MacMillan, 2009, p.742). Students
holding this misconception may think that since the “immovable” object cannot move,
the momentum of the moving object cannot be transferred to the “immovable” object, in
which case the momentum must be lost. This is incorrect as the “immovable” object will
be able to absorb some of the transferred momentum; also the moving object will be
able to keep some of its momentum and continue moving over or around the
“immovable” object. Finally, if there is still any momentum left and the moving object
55
transfers this momentum to the “immovable” object, the “immovable” object may move;
any “immovable” object can be forced to move if a great enough force is applied.
A fifth common misconception is that “the size of the force exerted by an object
hitting a surface was related only to the initial velocity of that object, rather than
to its change in velocity and hence its change in momentum” (Bryce & MacMillan,
2009, p.742). Although it is true that a greater initial velocity of an object striking a
surface causes a greater force of interaction, e.g., Fnet = ∆mv/∆t =1(0-10)/1 = -10N
versus Fnet = ∆mv/∆t =1(0-100)/1 = -100N, the initial velocity is not the only variable that
has an effect on the force of interaction. Both the mass of the object and the final
velocity of the object also affect the force of interaction between two objects. The
greater the mass of the object the greater the force of interaction according to the
equation: Fnet = ∆mv/∆t. The smaller the final velocity of the object the greater the force
of interaction, e.g. Fnet = m (v-u) /∆t = 1(5-10)/1 = -5N versus Fnet = m (v-u) /∆t = 1(0-
10)/1 = -10N.
A sixth common misconception is that since total momentum is conserved during a
collision, total kinetic energy is conserved during a collision (Bryce & MacMillan,
2009). Students holding this misconception are once again unclear on the difference
between momentum and kinetic energy, and do not understand that kinetic energy can
be transformed into other forms of energy. Students often rote-learn the rule that kinetic
energy is only conserved in elastic collisions and then get tied up into the circular
argument that inelastic collisions occur when kinetic energy is not conserved and kinetic
energy is not conserved during inelastic collisions, without coming to a real
understanding of what happens during elastic and inelastic collisions. Bryce &
MacMillan (2009, p.755) suggest explaining that:
Contact between two objects during a collision results in vibrations occurring in each. This means
that work is being done internally since the vibration entails movement through a small distance,
a consequence of which is that some of the original kinetic energy is converted into other energy
forms, like heat and sound. On the other hand, if the colliding objects are deemed to be perfectly
rigid, or if they do not make actual physical contact with one another, then these internal
56
vibrations do not occur and so no kinetic energy is lost as no internal work is done. Likewise,
where both objects are capable of returning entirely to their original shape after a collision (so-
called ‘‘super’’ rubber balls), it would also be termed elastic. There would be no net displacement
of the material in the balls and so all of the intermediate forms of energy are converted back into
kinetic energy.
Another problem related to the teaching of momentum is that school syllabi often focus
on isolated systems, which causes students to be confused about how the conservation
of total momentum applies to open systems. Teachers need to discuss the fact that the
total momentum in the universe is a constant; when a collision occurs momentum is
transferred not only between the bodies involved in the collision but also between the
colliding bodies and the surface, air and objects inside of the colliding bodies (Bryce &
MacMillan, 2009).
Finally, it would seem that most students are not persuaded about the differences
between momentum and kinetic energy. Teachers need to be granted more time to
discuss and co-construct these complex concepts with their students.
2.5.6.3 Misconceptions regarding the conservation of energy
In this section I will commence by discussing students’ misconceptions regarding the
conservation of energy. I will continue by discussing why these misconceptions are
constructed and how they can be remediated.
Driver and Warrington, as cited by Shymansky et al. (1997, p.575), have found that
“secondary students rarely used conservation of energy principles spontaneously to
analyze problems.” In addition, Shymansky et al. (1997, p.587) found that students
believe that energy is not conserved and that “Motion can create energy; force
creates energy; when you apply a force you use up energy; energy is created
when energy is working.” Duit and Haeussler (1994), Solbes, Guisasola and Tarín
(2009) and Trumper (1998) explain that students often believe that energy is a kind of
fuel or material entity, which may clarify why they think that it can be used up. Clearly
students struggle to understand the conservation of energy (Shipstone in Driver et al.,
57
1985) and speak of energy being created and used up or lost. These ideas are incorrect
because the scientific law of conservation of energy states that energy cannot be
created or destroyed, only transferred to other objects, transformed into other forms of
energy, or degraded.
The concept of energy is used often in everyday contexts and in everyday social
language it is normal to make use of phrases such as “I’ve run out of energy” (Scott et
al., 2007, p.49) or ‘‘consumption of energy’’ or ‘‘energy crisis’’ (Solbes et al., 2009,
p.266). Hence, the scientific idea that energy is not used up, appears to be far-fetched
in relation to everyday ways of thinking (Scott et al., 2007) and speaking. This everyday
manner of thinking and speaking about energy being used up or created is often
extended into the classroom environment by teachers, textbook writers and the
producers of audiovisual resources who attempt to simplify the abstract concept of
energy by relating it to everyday experience and social language. The idea that energy
is not conserved is also reinforced by the incorrect use of language that occurs during
the construction of explanations in other fields of Physical Sciences, such as electricity.
Teachers and textbook writers speak of “energy lost in power lines” and “lost volts”,
even speaking of the “generation of electricity” without discussing the transformation of
potential energy to kinetic energy, could leave a student with the idea that energy is
created. In modern times it is not uncommon to hear social media reinforcing the
message that energy needs to be conserved. This may reinforce the misconception that
energy can be used up, especially when students do not understand the transformation,
transport and degradation of energy.
These misconceptions are also strengthened by everyday observations as it is often
difficult to detect the transference or transformation of energy. For example, the energy
that is converted to heat due to friction often dissipates into the surroundings without a
noticeable change in temperature, making it hard to believe that energy was
transformed and that the surrounding particles have more internal energy.
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Another reason for the gap which exists between everyday energy concepts and
scientific energy concepts is the attempt to simplify matters by dealing with isolated
systems, which rarely exist. Students learn that “mechanical energy is conserved in
isolated systems” without a proper understanding of the energy transformation and
transference that takes place in open systems. Hence, when they are asked to relate
their understanding of energy to open systems, they fall back on the idea that energy is
lost.
The remediation of misconceptions regarding the conservation of energy may be
addressed by teaching all four of the “energy quadriga” (Duit & Haeussler, 1994, p.185).
The energy quadriga refers to the following four important aspects of the energy
concept: energy transformation, energy transport, energy conservation and energy
degradation. The degradation aspect of energy is often neglected in school Physical
Sciences, which makes it difficult for students to understand the conservation aspect
(Duit & Haeussler, 1994). The degradation of energy involves the transformation of
energy into useless forms of energy, during interactions and processes. Teaching
students about the degradation of energy may help to remediate misconceptions which
are reinforced by the “apparent contradiction between ‘energy conservation’ and the
‘need for energy resources’” (Solbes et al., 2009, p.267).
2.5.6.4 Misconceptions regarding electricity and electromagnetism
A great deal of research has been devoted to understanding the difficulties that students
experience in learning about electric circuits, (Bull, Jackson & Lancaster, 2010; Cheng
& Shipstone, 2003; Glauert, 2009; Periago & Bohigas, 2005; Pilatou & Stavridou, 2004;
Shepardson & Moje, 1999; Steinberg, 1983; Woods, 1994). According to (Mulhall,
McKittrick & Gunstone, 2001) the concepts related to electricity are particularly
problematic due to their highly abstract and complex nature. I will continue this
discussion by listing some of the misconceptions recorded in previous research:
59
• Electrical potential, potential difference, emf, and voltage are the same
thing (Cheng & Shipstone, 2003; Shipstone in Driver et al., 1985; Steinberg,
1983);
• Electrons carry positive charge (Bull et al., 2010);
• Potential difference is caused by current flow (Bull et al., 2010; Mulhall et al.,
2001; Shipstone in Driver et al., 1985; Steinberg, 1983);
• Voltage and current are the same (Bull et al., 2010; Shipstone in Driver et al.,
1985);
• Voltage across parallel branches is different for each branch (Bull et al.,
2010);
• Current can change within a branch (Bull et al., 2010);
• Current gets used up (Shipstone in Driver et al., 1985; Steinberg, 1983).
Research also shows that students tend to focus on what happens at only one point in a
circuit and forget that they are dealing with a multifaceted interrelated system (Cheng &
Shipstone, 2003; Steinberg, 1983). This localised reasoning makes solving circuit
problems problematic.
2.5.7 Strategies for the identification and reconstruction of misconceptions
Earlier in this chapter I have discussed the importance of teachers being aware of their
students’ prior knowledge and alternative conceptions. Pine et al. (2001, p.93) remind
us that: “If teachers are better informed about the types of false beliefs children are
likely to hold they will be quicker and better at identifying them, at helping children call
them to mind and make them explicit and at incorporating them into the process of
conceptual change.” In addition, students also need to be aware of their own alternative
conceptions, and how these conceptions relate to new conceptions they are studying.
Beeth and Hewson (1998, p.754) point out that “The important role of metacognition
and reflection in the development of autonomous students is widely acknowledged in
the educational literature.”
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Remediation or reconstruction of student misconceptions may, however, involve more
than mere student and teacher awareness. Tyson, Treagust and Bucat as quoted by
Canpolat (2006, p.1758) warn that bringing misconceptions to the attention of students
does not mean that they will change their conceptions. As these conceptions are
extremely resistant to change, teachers need to make use of alternative teaching
strategies that make use of student conceptions in the process of developing new
conceptions. Such alternative teaching strategies are discussed in the subsequent
sections.
2.5.7.1 Concept maps
Concept maps are a type of graphic organiser that can be used to represent the
relationships among concepts (İngeç, 2009). Trowbridge and Wandersee (1998, p.116)
describe concept maps as a hierarchy of concepts with a “superordinate concept at the
top”. The relationships between concepts are indicated by labelled lines. Teachers can
use concept mapping as a strategy to develop student conceptions by firstly guiding
students through the process of constructing a concept map and then by giving them
the opportunity to construct their own concept maps at the start of a new content area.
These concept maps can then be used by teachers to identify students’ preconceptions
and further inform the teaching process. According to Trowbridge and Wandersee
(1998, p.123)
Various aspects of a student constructed map may reveal alternative conceptions. The presence
of incorrect linkages forming invalid propositions is one indicator. The incorporation of concepts
not related to the superordinate concept or concepts that seem trite or irrelevant is another
indicator. … Missing concepts further indicate a student’s lack of understanding.
Since concept maps are intended to represent the “cognitive networks that have been
constructed by students in the process of learning” (Klassen, 2006, p.834) they can be
modified by the students throughout the learning process in order to allow for both
reflection on, and the extension of, the student’s understanding (Mintzes et al., 1998).
Unfortunately, the use of concept maps remains an uncommon practice in most
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Physical Sciences classrooms, largely due to the time constraints enforced by an
extensive curriculum.
2.5.7.2 Writing activities
The use of writing activities is another teaching strategy which can be used to develop
students’ alternative conceptions (Treagust et al., 2001); however, it too is not common
practice in Physical Sciences classrooms (Ruiz-Primo, Tsai & Schneider, 2010). Furtak
and Ruiz-Primo (2008) explain that writing activities are a more tangible way of
obtaining students’ conceptions. However, the use of writing activities requires practice
and is time-consuming as it requires students to express their understanding and to
think more deeply about why they believe what they do. Teachers also view the time
required to read and evaluate written products as excessive (Furtak & Ruiz-Primo,
2008; Mintzes et al., 2001). Hein (1999) suggests staggering writing assignments so as
to allow for enough time to present each class with valuable feedback. Another reason
for the limited use of explanation-type questions and writing activities is the over-
emphasis on numerical questioning in assessment. Also, many students do not have
the linguistic ability to cope with writing activities (Unsworth, 2001). On the other hand,
Hein (1999, p.140) explains that writing activities help to enhance students’
communication skills “whether English is their first language or not”.
Writing activities do not only have the potential to enhance the linguistic ability of
students, as mentioned previously they can also be used to help students organise their
thoughts (Treagust et al., 2001). According to Carlsen (2007) writing activities improve
students’ constructions of scientific concepts and help students to link new ideas with
prior knowledge. Since misconceptions form part of students’ prior knowledge, writing
activities can be used to help students’ link new ideas to their misconceptions and to
reconstruct their misconceptions. Unsworth (2001, p.586) argues that “developing
students’ knowledge and understanding in school science, and developing their
knowledge of the language forms that construct and communicate that understanding,
is one and the same thing.” Hein (1999,137) adds that writing “can be an effective
vehicle for allowing students to develop their critical thinking and problem-solving skills,
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as well as deal with their personal misconceptions regarding a specific topic in physics.”
Emig, cited by Grimberg and Hand (2009, p.504), argues that “because writing is often
our representation of the world made visible, embodying process and product, writing is
more readily a form and source of learning than talking.”
Teachers can use a variety of writing activities to diagnose and remediate
misconceptions. These include the writing of folder activities by students (Hein, 1999),
and Science Writing Heuristic (SWH) activities (Akkus, Gunel & Hand, 2007; Grimberg
& Hand, 2009; Hand, 2004). Hein (1999) describes her folder activities as a collection of
writing activities completed by a student and stored in a separate folder. These activities
require students to explain a problem or a concept, which was highlighted or discussed
during a class session, in their own words and with enough detail so that someone who
did not attend the class would be able to understand their explanation. These folder
activities should then be used to diagnose misconceptions and to plan teaching
activities which address the remediation of these misconceptions, rather than for the
purpose of grading or promotion. Akkus et al. (2007, p.1748) describe the SWH
activities as a different option to the conventional laboratory report, instead of
completing the aim, method, observations, results, and conclusion, students are
expected to complete sections on: “questioning, knowledge claims, evidence,
description of data and observations, methods, reflection on changes to their own
thinking.” By reflecting on changes to their own thinking, students are encouraged to link
new information to their preconceptions and to reconstruct their misconceptions. Thus, it
is evident that writing activities are an important teaching strategy, also with regard to
the remediation of misconceptions.
2.5.7.3 Group discussions and debates
Writing activities are not the only language-based activities which promote the
remediation of misconceptions. According to Rivard, cited by Akkus et al., (2007),
students’ understanding is enhanced when they are involved in verbal explanation
activities. Research has shown that students who verbalise their understanding are
more successful in conceptual development than students who do not verbalise their
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understanding (Jones & Carter, 1998). Carr et al. (1994) explain that students can
change their misconceptions when allowed to engage in conversation within a safe
environment. There are a variety of discussion activities which can be used to develop
conceptual understanding amongst students; in this section I will first discuss the use of
group discussions and then the use of debate in the Physical Sciences classroom.
In order for students to reconstruct their misconceptions they need to actively participate
in the learning process, hence Mintzes et al. (1998) encourage the use of activities such
as cooperative group work and debates. Jones and Carter (1998) explain that peer-peer
discussion helps students to interpret new knowledge and advances the development of
complex conceptions during the exchange of ideas. In order to maximise the conceptual
development of students during group work it is important to create a healthy learning
environment where students respect one another’s opinions and are not afraid to share
their understanding (Vosniadou, & Ioannides, 1998), or misunderstanding. Jones and
Carter (1998, p.273) also advise that the size of the groups will influence the type of
experience that the students will have; weak students should not be grouped together
as the construction process stops when no one in the group has the necessary
capability. In addition, Jones and Carter explain that each member should receive
cognitive roles such as “executive, sceptic, educator, and record keeper” to encourage
active participation of all group members.
The use of open debate in the Physical Sciences class allows students the opportunity
to explain their understanding, while coming to an understanding of how their
conceptions differ from the conceptions of other students (Nussbaum, 1998), and how
their misconceptions may be revised. Berland and Reiser (2008) argue that when
students are engaged in debate they are required to do more than merely explain their
understanding, they are expected to persuade others and to defend their
understandings. This often requires a change in the beliefs that teachers and students
hold concerning the nature of scientific knowledge and the process of learning, as they
are required to view Physical Sciences as “building knowledge with peers” (Berland &
Reiser, 2008, p.50). Nevertheless, investing time in student’ debate and group
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discussions promises enhanced conceptual understanding and the opportunity to
reconstruct misconceptions.
2.5.7.4 Practical investigations
Students’ understandings and misconceptions evolve as a result of the interaction
between their prior understanding and experience. Hence it is important for teachers to
provide students with experiences such as practical experiments which have the
potential to enhance their understanding and remediate their misconceptions. Ausubel
(in Novak, 2004, p.32), maintains that “students require concrete-empirical props to
develop abstract concepts.”
Vosniadou and Ioannides (1998) warn that teachers need to be careful to choose
experiments that will provide the cognitive dissonance necessary for conceptual
change, otherwise students may observe only those features which support their
misconceptions (Pine et al., 2001). In addition, it is important to make use of “open-
ended investigations that devolve as many decisions as possible to the students”
(Moore & Harrison, 2004, p.1), as opposed to the “closed work” type (Simon & Jones,
cited by Gilbert et al. 1998b, p.194) where the aim, method, method of data analysis,
even the results, are prescribed by the teacher. Otherwise, practical activities may
become just as meaningless to students as rote learning and recipe-type calculations
and just as ineffective in the remediation of misconceptions; especially when students
do not have the skills and understanding required to process their observations (Novak,
2004). Campanario (2002, p.1097), warns that students often draw incorrect
conclusions during practical activities and that “the experience, contrary to expectations,
does not guarantee change of conception by itself.” In addition, Hart, Mulhall, Berry,
Loughran and Gunstone (2000) add that research has shown that experimentation does
little to promote meaningful learning, due to factors such as the cognitive overload of
students, a lack of understanding of the purposes involved during experimentation and
the fact that students’ observations differ from what is expected due to their differing
conceptual frameworks. Hence, it may be necessary to enhance practical
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investigations. I will continue this discussion by highlighting three contemporary
teaching strategies designed to improve practical investigation.
Predict-Observe-Explain (POE) is a teaching strategy where students are shown an
authentic situation and are then asked to give their prediction about how a specific
change to the situation will affect the situation. Next they get to observe the changes
and write down their observations. Lastly, the students attempt to reconcile their
predictions and observations (Gunstone & Mitchell, 1998). POEs can be used to elicit
students’ ideas and misconceptions; they can also be used to enhance student
understanding and remediate misconceptions at various stages during the teaching of a
specific content area (Furtak & Ruiz-Primo, 2008).
Science Writing Heuristic (SWH) activities, as discussed in the previous section, can
also be used to enhance traditional practical investigations. SWH activities are a more
effective manner of writing the report on a practical investigation; it allows students to
reflect on changes in their understanding and to reconstruct their ideas on paper.
Another type of experiment which can be used to remediate misconceptions is the
thought experiment. Thought experiments are “a way of exploring the logical
consequences of a set of ideas in various idealized situations, including imagining what
happens when the effects of a variable become extremely small or are entirely
eliminated” (Smith, 2007, p.355). Thought experiments can be used to allow students
the opportunity to explain and develop their ideas.
2.6 CONCLUSION
At the beginning of this chapter I defined the key concepts of this study. In searching for
the definitions of misconceptions, pre-knowledge and explanations, I found them to be
complex concepts that have elicited a variety of different opinions and theories with
regard to their meanings. I came to the conclusion that misconceptions are alternative
conceptions that form part of students' pre-knowledge and that these conceptions are
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under construction and form useful anchors for the accommodation of new information.
Pre-knowledge is the students’ conceptual framework as it exists prior to formal
education events. Pre-knowledge is important because new knowledge must be linked
and re-crafted into students’ pre-knowledge. Explanations are also an important part of
learning. They are descriptions and rationalisations of students’ understandings which
can be used for the diagnosis of misconceptions. However, explanations are also
learning tools, because knowledge is constructed and misconceptions can be re-crafted
during the formulation of explanations.
After defining the key concepts of this study I went on to discuss the theories which form
the theoretical and conceptual framework of my study. According to the theory of
constructivism knowledge is not merely transferred from the teacher to the student, it is
interpreted in terms of the student’s pre-knowledge and constructed by the student.
Hence, misconceptions cannot be removed and replaced by teaching the student the
correct conceptions. Instead, teachers need to be aware of misconceptions, so that they
can support students in the re-crafting of these misconceptions. According to the theory
of social constructivism teachers can influence the construction and re-crafting of
knowledge, because knowledge is seen to be constructed socially by the student and
various social role players and factors. In addition, teachers and other social role
players and social factors, such as students’ peers, family, media, textbooks and
classroom environment, may also have a negative effect on learning in terms of
providing information which could be crafted into a misconception. In order for teachers
to support the re-crafting of student’ misconceptions they need to diagnose these
misconceptions. Students’ explanations can provide valuable information with regard to
the misconceptions they hold. In this study, I used Dagher and Cossman’s conceptual
framework of explanation-types to classify explanations and to gain information
regarding the student misconceptions revealed in these explanations.
Next I discussed the nature of misconceptions which can either be seen as stumbling
blocks which hinder learning, or as building blocks with which new knowledge is
constructed. I continued by discussing the complex process of conceptual change which
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is a gradual process of re-crafting pre-knowledge, including misconceptions. I also
discussed the various sources of misconceptions from the individual to various other
social role-players and social factors. I reviewed studies on the relationship between
misconceptions and language, assessment and context. I found that language,
assessment and context can be useful in diagnosing misconceptions, but may also
hinder the diagnosis of misconceptions. Furthermore, I found that language;
assessment and context may be used to remediate misconceptions, but may also
reinforce misconceptions. I went on to identify specific student misconceptions in the
field of Physics, and discussed contemporary teaching strategies that can be used to
remediate misconceptions.
In the next chapter I will discuss the method that I used to collect data on the
misconceptions held by a sample of grade 12 Physical Sciences students.
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CHAPTER 3
RESEARCH DESIGN AND METHODOLOGY
3.1 INTRODUCTION
In this chapter I will discuss the selection of an appropriate research design genre and
research methodology for this study. According to Mouton (2001), the research design
genre can be associated with the architectural plans for a house, and the research
methodology with the construction process. Mouton (2009) also emphasises that a
research framework should not start at the design and method, but rather with an
outline of the researcher’s beliefs of what knowledge is, that is, an epistemology. In
other words, just as one needs to reflect on your beliefs regarding what a house should
be, in order to select a suitable plan; researchers need to reflect on their beliefs
regarding knowledge, in order to select a suitable design genre. It is also important for
researchers to behave ethically as they reflect on their epistemology, select a research
genre and construct suitable evidence. I will discuss the ethical considerations related to
this study in this chapter.
Mouton’s (2009) metaphorical comparison of the construction of a house with the
construction of a research study suits this study because it is framed in the theories of
constructivism and social constructivism. Therefore, the structure of this chapter will
continue along the lines of the construction metaphor. I will commence by describing the
structure to be constructed – the evidence for the research questions. Then I will
discuss my beliefs regarding the knowledge to be constructed – epistemology, the
research plan for the construction process – research genre, the construction process –
research methodology, the collection of construction materials – data collection, the
construction of evidence – data analysis and, lastly, the cleaning up of the construction
site – data storage.
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3.2 THE STRUCTURE TO BE CONSTRUCTED – RESEARCH QUESTIONS
The poor performance of students during the 2008 NSC Physics examination generated
the need to construct an understanding of the common misconceptions held by Physical
Sciences students. Part of the understanding that needs to be constructed also includes
knowledge regarding the performance of students in explanation-type questions, the
types of student explanations that reveal misconceptions and what explanation-types
reveal about student misconceptions. More specifically, answers to the following
research questions need to be constructed:
1. What are the common student misconceptions that are revealed in a high stakes
Physics examination?
2. How do students perform in explanation-type questions?
3. What do explanation-types reveal about student misconceptions?
3.3 BELIEFS REGARDING THE KNOWLEDGE TO BE CONSTRUCTED –
EPISTEMOLOGY
The theoretical framework for this study is the constructivist learning theory social
constructivism. Constructivism is the theory that “knowledge is not transmitted directly
from one knower to another but is actively built up by the student” (Driver et al., as
quoted by Nola in Matthews, 1998, p.56). Social constructivism emphasises the idea
that students do not construct knowledge individually, but rather through social
interactions (Vygotsky, 1978). By selecting social constructivism as the epistemology
which frames this study, my perspective regarding what a misconception is differs from
a positivist’s perspective. From my social constructivist perspective misconceptions are
co-constructed by students together with other social role-players and are not merely
incorrect conceptions which can be remediated by transference of the correct
conception.
The epistemology of social constructivism also influences my choice of research genre,
as the research genre needs to generate evidence matching the belief that
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misconceptions are a social construct. According to Mouton (2009), the researcher
needs to consider what type of evidence constitutes suitable evidence with regard to the
research questions when selecting a research genre. Mouton introduces three modes of
reasoning with regard to the type of evidence, which he call research logics. I will
continue by rationalising about what type of evidence is suitable for this study, by using
Mouton’s research logics as a guideline.
Mouton’s first pair of research logics is the logics of contextualisation and
generalisation. The logic of contextualisation as opposed to the logic of generalisation
involves the in-depth investigation of a case or small number of cases. My study is
conducted within the logic of contextualisation, because the students’
misconceptions, as evident in a sample of answer scripts, have inherent value and need
not be representative of the larger population. The fact that these misconceptions may
not be held by most students, and hence cannot be generalised, does not take away
from the importance of teachers becoming more aware of possible misconceptions and
their relation to student explanations. Knowing more about students’ misconceptions will
assist teachers in being better prepared to adapt their teaching strategies.
Mouton’s second pair of research logics is the logics of discovery and validation. The
logic of discovery within research implies that the research generates new hypotheses
and frameworks as opposed to the logic of validation which tests existing hypotheses
and frameworks. My study involves the logic of discovery as I planned to ascertain
common misconceptions and their relation to student explanations, instead of testing a
hypothesis regarding student misconceptions.
Mouton’s third pair of research logics is the logics of synchronicity and diachronicity.
The final logic or reasoning underlying my study is the logic of synchronicity.
Synchronicity refers to the examination of a situation over a period of time, whereas
diachronicity refers to examination of a situation at a given point in time. Although my
study focused on the 2008 matric examination, the misconceptions evidenced in the
exam scripts were constructed and re-constructed gradually over a period of time. In
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this study I not only aimed to find out what misconceptions students hold, but to find out
more about the process through which these misconceptions were constructed and how
they influenced the explanations that students construct.
3.4 RESEARCH PLAN FOR THE CONSTRUCTION OF KNOWLEDGE –
RESEARCH GENRE
The nature of the data required for this study informed the selection of a suitable
research genre. The data required were detailed descriptions of what misconceptions a
specific group of students hold and what their explanations expose about the nature of
these misconceptions. The context to be investigated was the performance of grade 12
students during the NSC examination of 2008. The exam scripts of these students had
been made available for research and they contained a great deal of information on
what students understand and the misconceptions they hold. An analysis of the textual
content in the students’ exam scripts would yield the data required. The analysis of
content in any form of communication is known as content analysis (Breecher et al.,
1993). According to Kaplan (1943, p.230) content analysis “attempts to characterise the
meanings in a given body of discourse in a systematic and quantitative fashion.”
Krippendorff (2004, p.18) explains that content analysis is a “research technique for
making replicable and valid inferences from texts (or other meaningful matter) to the
contexts of their use.” The methodology of content analysis involves the exploration of
communications in order to gain an answer to the research question (Thomas, 2003).
Characterising and describing the meaning of student explanations from their exam-
script responses would yield suitable data regarding their misconceptions, therefore
content analysis was selected as the suitable research genre for this study.
Early definitions of content analysis specified the quantification of data (Kaplan, 1943).
Textual data can be quantified by counting the occurrence of specific words or themes
(Franzosi, n.d.). The identification and classification of specific words or themes is
known as coding. Coding the exam-script responses in this study would be useful.
Specific codes could be allocated to certain misconceptions and explanations and then
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these codes could be counted in order to determine the frequency of student
misconceptions and explanation-types.
An indication of the frequency of misconceptions revealed in the 2008 exam scripts
would serve as an interesting introduction to this study. However, the aim is to construct
a deeper understanding of student misconceptions. In other words, the focus is not so
much on the quantification of the data, but rather on the qualitative description of the
data. Content analysis occurs in many forms, and later definitions indicate that
quantification need not be the only focus of such an analysis (Krippendorf, 2004).
According to Shaw (2006) “The perspective which views content analysis as a purely
quantitative method fails to recognize the degree to which interpretation of texts
underlies the development of a coding scheme.” Franzosi (n.d., p.189) argues that “To
think in terms of a quantitative versus a qualitative approach to texts is a misguided
approach. Each has strengths and weaknesses.” The best approach is probably a
combination of counting common themes and regularly delving deeper into the meaning
of those themes.
The second phase of this study involves the collection and analysis of interview data
with the purpose of further clarifying the nature of student explanations and
misconceptions. White and Marsh (2006) explain that content analysis has been used to
analyse interview transcripts. They emphasise that the most important criteria for
selecting data for a content analysis is the value of the data with regard to supplying
valuable evidence for answering research questions. Since both the exam script and
interview data contain valuable information regarding student misconceptions, I planned
to conduct a content analysis of both of these sets of related communication.
3.5 CONSTRUCTION PROCESS – RESEARCH METHODOLOGY
In order to construct evidence for this study a suitable methodology needs to be
selected. The methodology that best fits my content analysis is a qualitative
methodology that allows me as the researcher to position myself inside the social world
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(Denzin & Lincoln, 2000) as a co-constructor of meaning. My goal is similar to that
which Bogdan and Biklen (1998, p.38) refer to in stating that “The qualitative
researchers’ goal is to better understand human behaviour and experience. They seek
to grasp the processes by which people construct meaning and to describe what those
meanings are.” Franco and Taber (2009, p.1929) explain that a qualitative research
technique is chosen because of the “desire to investigate student thinking in depth” and
“for fine grained exploration of students’ ideas.”
Even though my research will take the form of a qualitative study, I will collect both
numeric and textual data in order to induce or construct a description of student
misconceptions, explanation-types and the relationship between student explanations
and misconceptions.
3.6 COLLECTING MATERIALS – DATA COLLECTION
Since the aims of this study are to identify common misconceptions as evidenced by the
2008 NSC Physics examination and classify them according to the explanations offered
by the students, my primary source of data was a sample of student exam scripts.
However, Schuster (1983) argues that one cannot deduce anything concerning
students’ misconceptions without probing their way of thinking. Therefore, I decided to
interview a sample of students in order to probe their thinking to enable me to construct
a richer description of the misconceptions found in the student exam scripts. I also
included teachers in the interview sample, as they are co-constructors of the knowledge
that their students construct, and I was also interested to find out to what degree they
are aware of the misconceptions held by their students.
In this section, I will discuss the processes of identifying misconceptions and collecting
data from both the student exam scripts and the interviews. I will also discuss the
various ethical considerations that formed part of this study.
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3.6.1 Exam-script data
A total of 218 156 grade 12 students, 17-18 years of age, wrote the 2008 NSC Physics
examination (Appendix H). A random sample of 921 Physics examination scripts was
provided to the University of Johannesburg (UJ) as part of a script analysis project that
was commisioned by the DOE. These were scripts that had already been marked by
external examiners appointed by the DOE. The sample was selected randomly from the
population of students who wrote the 2008 NSC Physical Sciences examinations in
Gauteng. The sample of 921 scripts comprises 0, 4% of the total population of 2008
grade 12 Physical Sciences students. Although this is a small percentage of the total
population, the sample has inherent value and allows for a more in-depth analysis of
student misconceptions.
3.6.2 Interview data
I decided to probe the misconceptions identified in the exam scripts in a second phase
of the study. The second phase of this study involves interviewing students and
teachers. In this section I will discuss the rationale for using interviews and the process
that I followed to collect data from the interviews
3.6.2.1 The rationale behind using interviews to supplement the exam-script
data
I decided to supplement the exam-script data with interview data for two reasons.
Firstly, the interviews would allow me to probe students’ thinking with regard to their
misconceptions. According to Schuster (1983), one needs to explore students’ thinking
in order to illuminate students’ misconceptions. Also, qualitative interviewing
endeavours to illuminate the interviewee’s ideas (Kvale, 1996). Secondly, the use of
both exam-script data and interview data would enhance the validity of this study.
Burton, Brundrett and Jones (2008) and Creswell (2003) explain that the use of multiple
sources of data, which is known as the triangulation of data, helps to ensure the
credibility or validity of research data. Research findings are valid when the research
instruments measure what they claim to measure (Conrad & Serlin, 2006) and when the
findings make sense to the group of people reading the study (Miles & Huberman,
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1994). Although the addition of interview data enhanced the validity of this study it was
not the only method employed to improve the validity. I validated my inquiry further by
applying the methods proposed by Henning et al. (2004) that is: continually checking,
questioning and interpreting my findings; aligning my research methods with my
research question; communicating information regarding the research process and
findings with the research participants and other stakeholders; and ensuring a degree of
“pragmatic validity” by making my findings available for use by the research participants.
I discuss the follow-up communication with the research participants in section 3.6.2.9.
3.6.2.2 Surveying the site
According to Henning et al. (2004, p.143) “surveying the site and gaining entry” are the
steps that follow pre-research activities in the design process. I did not have access to
interview the students whose exam scripts were analysed, because the NSC is an exit
examination. I therefore sought a sample of students from another location, so that I
could probe them on the common misconceptions prevalent from the exam-script
analysis. I decided to conduct the interviews with a later cohort of students to the one
which had written the high stakes national examination. The site which I chose for
conducting the interviews is a high school that is conveniently located. The high school
is an English medium, multicultural and urban school.
3.6.2.3 Gaining entry and acquiring permission — ethical concerns
In order to gain entry and permission to conduct research at the selected high school, I
wrote a letter to the head office and relevant district office of the Gauteng Department of
Education (GDE). I informed them of my study and its’ aims and requested permission
to conduct my research. The letters from the GDE granting permission are included as
appendix B – C.
After receiving permission from the GDE, I wrote letters to the school principal, teachers
and parents requesting written consent to conduct the research and a letter to the
students requesting their assent to participate in the research (appendix D – G).
According to Henning et al. (2004) it is important that consent is informed, so I included
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information regarding the background and purpose of my study as well as information
about the nature and duration of the pre-interview test and interviews. The following
ethical considerations as described by Greene and Hogan (2005, p.81) were also
explained to the principal, teachers, parents and students and adhered to during the
research:
1. Welfare
The students were informed that the research may assist them in identifying
misconceptions which they may have regarding Physics. They would receive
feedback regarding common misconceptions as well as the correct answers for
the explanation-type questions extracted from the 2008 NSC Physics
examination.
2. Protection
The students were informed that the worksheets would not be used by the school
for any form of assessment and that they would not be required to study anything
beforehand.
3. Provision
The students were informed that their participation may contribute to enhancing
teacher awareness of student misconceptions in the field of Physics.
4. Choice and participation
The students were informed that they have the freedom to either agree to or
refuse participation, with the choice to withdraw from the study with impunity.
They were also assured that their identity and responses would be kept
confidential.
After gaining written permission from the GDE and research participants to conduct the
pre-interview test and interviews, I submitted the letters of consent, together with my
research proposal, to UJ and received ethical clearance.
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3.6.2.4 Pre-interview testing for the purposive sampling of interview
participants
I selected a high school to participate in this study as a convenience sample. However, I
needed to find students who held the same misconceptions as those revealed in the
exam-script analysis which took place prior to the selection of the interviewees.
Selecting participants who can best illuminate a specific research problem is known as
purposive sampling (Henning et al., 2004).
In order to select those students who held the same common misconceptions as
identified in the exam-script data, I compiled a pre-interview test. The pre-interview test
consists of the same 12 explanation-type questions used in the exam-script
classification. The pre-interview test (Appendix J) was compiled in a worksheet format
so that students might find it less stressful. A few different versions of the worksheet
were copied, each version differing only in the order in which the questions were asked.
I did this so that if students did not finish the worksheet, or lost concentration, I would
still have enough data on each different question.
The 18 grade 12 Physical Sciences students at the selected school wrote the pre-
interview test shortly before their preliminary examinations; hence they had already
worked through all of the subject content that was included in the pre-interview test. The
students wrote the pre-interview test under the supervision of their teacher and I marked
the tests according to the DOE memorandum (appendix I). After marking the tests I
analysed the tests in order to identify students who had constructed similar
misconceptions as those that were most prevalent in the exam-script sample. I
discerned 10 students who displayed similar misconceptions to those from the exam-
script classification. These 10 students formed the student interview sample.
The similarities between the student interview sample and the exam-script sample are
that they are both a multi-cultural group with a majority of Africans, they include both
male and female students, they include students with a range of academic ability and
they both studied the same curriculum. A difference between the student interview
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sample and the exam-script sample is that the average language ability of the interview
sample, as observed in the pre-interview test, was better than that of the exam-script
sample. However, the misconceptions that were identified in the exam scripts were
identified in scripts where the language ability of the students was average. Very few
misconceptions could be identified in exam-scripts where the language was very poor.
In other words, students which had clearly contructed misconceptions in the exam
scripts used similar language to the students in the interview sample. The socio-
economic backgrounds of the students in the interview sample and the students in the
exam-script sample also differed. The students in the interview sample attended an
urban school with slightly higher than average school fees and with better resources
than most rural schools. On the other hand the students in the exam-script sample
came from either urban, township or rural schools. Despite the differences between the
students in the interview sample and the students in the exam-script sample I found
evidence of similar misconceptions in both samples, thereby verifying that
misconceptions are shared amongst a diversity of cultures, abilities and genders (Alzate
& Puig, 2007; Driver et al., 1985; Mintzes, et al., 1998; Scott et al., 2007; Vosniadou &
Ioannides, 1998).
I planned to include teachers in the interview sample in order to enquire about the
extent to which they are aware of the misconceptions held by their students, the
possible sources of misconceptions and the strategies they are using to address these
misconceptions. The school I had selected had only one grade 12 Physical Sciences
teacher. I decided to interview her as she would have useful information regarding the
misconceptions held by her students from a teachers’ point of view. Since the grade 12
Physical Sciences teacher had only been teaching for a few years, I decided to include
her head of department in the teacher interview sample. The head of the Sciences
department had been teaching Physical Sciences for many years and it was expected
she would have knowledge on students’ misconceptions. I decided that interviewing two
teachers and 10 students would provide sufficient data to help clarify the exam-script
data.
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3.6.2.5 Choosing discursive interviews as the research tool
I chose to conduct discursively oriented interviews as opposed to standardised
interviews, because it would better match the design of this study. According to Warren
(2001, p.83), “the epistemology of the qualitative interview tends to be more
constructionist than positivist.” In discursively oriented interviews, data or information is
co-constructed through the interview process by both the interviewee and interviewer.
Whereas in standardised interviews, facts are merely collected from the interviewees
(Warren, 2001). Henning et al. (2004) argue that the interview- interaction and
discourse influences the data, no matter how neutral the interviewer attempts to be. In
the discursively oriented interview, the data are constructed by the interaction and
characteristics of the interaction, such as trust, ability to express oneself, methods of
expression, class and status differences, social identity, culture and the perspectives of
both the interviewer (reflected in the design of the interview questions) and the
interviewee. Although the researcher has the responsibility of taking control, the
discursively oriented interview places the researcher and the participants in more
equitable roles. According to Glesne in Falk and Blumenreich (2005), it is the
interviewee’s responsibility to make deeper meaning of the students’ experiences.
A standardised interview would yield more superficial information because the students’
responses may be constrained due to the unnatural interaction of the interview and the
limiting structure of the research questions. Discursively oriented interviews allow the
researcher to probe the students’ responses, thus enabling richer data construction.
When given a limited answer, I asked the participants to tell me more about their ideas,
why they held those ideas and/or where they got the ideas from, instead of rigidly
adhering to the pre-set questions. Southerland, Smith and Cummins (2000, pp.91-92),
explain that:
Interviews can provide valuable insights into a student’s meaning. Because the
teacher/researcher’s interpretations are grounded in the student’s voice, we may more fully
understand what a student knows and how she can apply that knowledge. Such thick descriptions
of several students’ conceptual frameworks in a classroom are invaluable tools in planning
classroom instruction.
80
3.6.2.6 Planning the interviews
Despite having the freedom to deviate from pre-set questions in order to move with the
interviewee’s train of thought, it was important to carefully prepare a framework of pre-
set questions, so that I could get the interviewee thinking along the right track. In order
to prepare probing questions, I studied each student’s responses to the pre-interview
test. I then compiled a separate set of questions for each student, specifically probing
those responses which resembled the common misconceptions found in the exam-
script data. Two examples of the probing questions that formed part of my interview
schedule are: “Why do you think that cars with a greater mass exert a greater force on
lighter cars during a collision?” and “Where do you think you got the idea that heavier
cars exert a greater force on lighter cars during a collision?”
I also set interview questions for the two teacher interviewees as part of the interview
schedule. The questions that I used for both the students and teachers were open-
ended questions, questions requesting individual thoughts, experiences and opinions.
One example of an open-ended question which formed part of my interview schedule is:
“From your point of view, what would you say are the main sources of student’
misconceptions?” Before setting out to use the interview schedule of questions
(appendix M), I gave them to my supervisor for his input.
Next I asked the teachers which time would be most suitable for both their interviews
and the students’ interviews. I wanted to ensure that students did not lose any teaching
time, so I asked if the afternoons would be suitable. The teachers explained that since
the students were writing exams they would prefer to be interviewed during the long
waiting periods that they had in between practical exams. Together with the teachers
we set up an interview timetable and I arranged with the school’s librarian to conduct
the interviews in a quiet room attached to the library. Prior to each interview, consent
was requested from each student interviewee, teacher interviewee and from the head of
department to tape-record the conversation. I explained that this was necessary in order
to transcribe the interviews.
81
3.6.2.7 Interview procedure
The students and teachers were interviewed individually. According to Henning et al.
(2004, p.75), interviews share a “typical flow”. I conducted my interviews according to
the “typical flow” described by Henning et al., I discuss this flow next:
1. Scene-setting
At the start of each interview I warmly greeted the interviewee and made him or her
feel as comfortable as possible. I explained to both the students and their teachers
that sharing their experiences, ideas and opinions would be valuable in assisting
both me and them to better understand students’ ideas so that we may help them. I
also briefed them on the course that the interview would take. I explained to the
students that I would be asking them a few questions about the ideas they
expressed in their pre-interview test. I explained to the teachers that I would be
asking them about their experiences and opinions regarding student misconceptions
in Physical Sciences.
2. Providing the interviewee with a set of pre-set questions to scan
Henning et al. explain that this step is not compulsory as it may cause the
interviewee to anticipate certain responses thereby limiting the conversation. As a
result, I excluded this step.
3. Questions and answers
Next, I probed students on their misconceptions. I ask them to explain the reasoning
behind their answers to the questions in the pre-interview test. I asked questions
like: “Why do you think that cars with a greater mass exert a greater force on lighter
cars during a collision?” I also asked the teachers about their experience of
students’ misconceptions, the strategies that they used in an attempt to remediate
misconceptions and their opinion on possible causes of misconceptions. I listened
carefully to both the students and teachers, keeping eye contact and allowing for
pauses. When interviewees did not provide enough information I asked them to
elaborate on what they had said. When their response deviated from what I had
82
prepared, but remained relevant to the study, I asked them to explain their thoughts
and the possible origin of their ideas.
4. Summarise some of the conversation
Henning et al. state that interviewers can verify that they have correctly understood
the interviewee by summarising parts of the conversation as it evolves. The
following interview extract illustrates this part of the interview:
Researcher: You wrote: “the driver of the truck will take less impact because of its size and
mass, and the truck will make the car move in the same direction.” Tell me more
about why you think the truck will take less impact because of its mass?
Student 2: I think it is because of the material which it is made of, it’s, a car it’s more like a, I
don’t want to say plastic, because there are some parts, like it’s made out of
plastic, more than the truck, you know, …
Researcher: Ok, you said that the truck will take less impact on its materials that it’s made of,
what is impact?
Student 2: Impact is the, (pause) for example, a car right, um, put it um,… ish, ok, …, impact
is the amount of force um, an object can take, but then, it gets destroyed in a kind
of way, like when it impacts, yah.
Researcher: So it’s the amount of force that it can take?
Student 2: Yah.
Researcher: O.K., so you are saying the, the truck can take more force than what the little car
can take.
5. Clarification of concepts
The interviewer may also ask the interviewee to explain the meaning of certain
concepts used by the interviewee. This practise is particularly helpful as it enables
the interviewer to find out what the interviewee comprehends about the concept.
The following are examples of such clarification, extracted from the student
interviews:
Researcher: You said that: “the cut-off switch is important because once there is an overflow
of power into one plug and it is damaging your devices it is not recommended if
83
such a similar thing happens to pull the plug connected because that can result in
your death.” What is power?
Student 2: The amount of work that can be done.
Researcher: You wrote: “wire P is a better conductor, because it is at a higher potential
difference than Wire Q.” Tell me more about why, uhh, the higher potential
difference would make it a better conductor. Why do you think it works like that?
Student 2: For some reason I think when something has the potential the high potential
difference it has the better conductor.
Researcher: O.K., what is potential difference?
Student 2: It’s the voltage of the umm … conductor or...
Researcher: O.K, and what is voltage?
Student 2: The measurement of umm …aah …umm …can’t really think what that is now um
(pause).
6. Keep an eye on the recording
Henning et al. reminds interviewers to check the recording device periodically during
interviews. Since I was using a tape recorder, which runs out of tape every 40
minutes, this was valuable advice.
7. Rounding off
After running through the pre-set questions and gaining clarification where
necessary, the time was almost up, so I checked if there was anything that the
participant would like to add or ask. Then I expressed my appreciation for the
participant’s participation and greeted the participant.
Each student and teacher interview followed this same process and lasted
approximately 30 minutes.
3.6.2.8 Recording the interview data
I transcribed the first interview word for word, typing and saving the data directly onto
my computer. During the transcribing process I already started to notice correlations
between the interview and exam-script data. Henning et al. (2004, p.127) states that:
“Qualitative analysis takes place throughout the data collection process. As such the
84
researcher will constantly reflect on impressions, relationships and connections while
connecting the data.” After transcribing the first set of data, I proceeded with the next
interviews. As I continued with the interviews I realised that there were similarities
between the students’ ideas and understanding, as well as similarities between the
interviewees’ responses and the exam-script responses. I recorded these connections
as I went along. I completed the interviews over a period of four days. Thereafter, I
transcribed the rest of the student and teacher interviews verbatim, including other
details such as pauses. The transcripts of both the student and teacher interviews are
included as appendix N – O.
3.6.2.9 Follow-up communication with the interview participants
Since research should be beneficial to the participants (Greene & Hogan, 2005), I gave
the teachers and students feedback on the findings of the study. I returned the students’
worksheets to them, with individual, detailed feedback. Copies of each student’s
worksheet were given to the teachers. I also included sufficient copies of a
memorandum with extended explanations and common misconceptions for the perusal
of both students and teachers. The extended memorandum is included as appendix K.
3.7 CONTRUCTING EVIDENCE – DATA ANALYSIS
In this study both a qualitative and a quantitative analysis of the exam-script data was
conducted. Thereafter, a computer-assisted qualitative analysis of both the exam-script
and interview data was conducted. These processes of analysis are discussed in this
section.
3.7.1 Qualitative analysis of the exam-script data
In this section I will discuss how I identified student misconceptions as revealed in the
exam-script data and why I focused the analysis on the student responses to
explanation-type questions. Next I will discuss how I designed an explanation-
classification grid and used it to classify the student misconceptions according to their
explanations.
85
3.7.1.1 Identifying the misconceptions
Since this study aims to identify common misconceptions, it was necessary to decide
exactly how misconceptions would be identified from student responses. According to
Clerk and Rutherford (2000, p.704), a misconception “fails to match the model accepted
by the mainstream science community in a given situation.” My working definition of a
misconception, as discussed in chapter 2, is: a misconception is a believable
conception which differs from the corresponding scientific conception. Although it
would be difficult to measure the degree to which students believe their alternative
conceptions, I would be able to identify student conceptions that differ from the
corresponding scientific conception. Hence, I decided that I would classify student
responses that are conceptually different to the answers supplied in the memorandum
as a misconception.
After an initial literature review, it became evident that I should not use the students’
responses to the multiple choice questions to identify possible misconceptions.
Although many research instruments employ a multiple-choice format to identify
misconceptions, Clerk and Rutherford (2000) raise questions concerning the validity of
using multiple-choice questions for diagnosing misconceptions. They argue that
students often misinterpret the question due to language barriers and then choose an
incorrect answer based on the misinterpretation. Also, Larrabee, Stein and Barman
(2006) point out that one of the main problems with this format is that it is difficult to
develop alternative responses that reflect the full range of students’ conceptions,
including misconceptions, about a particular idea. Students may also guess an incorrect
answer because they really do not know the subject content. Such incorrect answers
may then be misdiagnosed as a misconception.
Studies have revealed that calculation problem-solving questions have also been
problematic for uncovering misconceptions because students may be able to use
algorithms to solve these problems but may lack conceptual understanding (Cromley &
Mislevy, 2004; Goldring & Osborne, 1994; Hunt & Minstrell, 1994; Papaevripidou,
Hadjiagapiou & Constantinou, 2005). In view of these difficulties in identifying and
86
analysing student mirsconceptions, this study attempts to broaden our understanding of
student misconceptions by classifying misconceptions evident in student explanations.
Hence, I set about identifying the questions in the examination paper which would elicit
an explanation response from the students. Twelve of the questions from the
examination are explanation-type questions.
3.7.1.2 Designing the classification-grid
I designed the classification-grid as a research instrument with the purpose of
classifying misconceptions according to the explanation-type offered. I based my design
on the ten Dagher and Cossman explanation-types. Dagher and Cossman (1992)
generated ten types of explanations while exploring the nature of explanations in high
school classrooms. Moore and Harrison (2004) then employed their categorisation of
explanation-types in describing students explanations on the floating and sinking of
objects. These ten explanation-types can be described as follows:
Analogical: A story that parallels the unfamiliar phenomenon, e.g., “it can float because
it’s like a submarine.”
Anthropomorphic: Attributing human characteristics to a phenomenon, e.g., “she floats
because she is lighter.”
Functional: Explained as a consequence of function (natural), e.g., “It floats because of
the air in it.”
Genetic: Uses a sequence of events (what, not why) and resembles description by
stating “what happens, not why it happens”, e.g., “it floated on top of the water.”
Mechanical: A relationship because of physical (shape/design) properties (pressure),
e.g., “it floats because of its shape.”
Metaphysical: Where a supernatural agent is identified as a cause of the phenomena,
e.g., “God made it float.”
Practical (how to): Instructions of how to perform physical or mental operations, e.g., “to
float you need to do …” this is regarded as description rather than explanation.
87
Rational: A clearly identifiable scientific statement or story where scientific evidence is
given for a claim, e.g., “a boat floats because the up-thrust from the water equals the
weight.”
Tautological: This is a circular story, e.g., “it floats because it is made to float.”
Teleological: It has to or needs to happen as part of the phenomena, e.g., “boats float
because we need them to float.”
I designed the misconception classification-grid as a table, with spaces to fill in data with
regard to a single student’s exam responses. The grid includes columns representing
the ten Dagher and Cossman explanation-types and rows representing the 12
explanation-type questions asked in the examination. The grid enables one to classify
the student responses as a particular type of explanation. This was critical in my
analysis as I was then able to understand the characteristics of the explanation, which
led me to effectively diagnose a misconception that was inherent to a type of
explanation. Besides the columns for the ten explanation-types, I included columns to fill
in when the student held no misconception or when the classification of the
misconception was inconclusive. Responses that were constructed so poorly that their
meaning was unclear were to be classified as inconclusive. I also included spaces to
record the marks obtained by the student for each explanation-type question, the total
achieved by the student for the explanation-type questions and the total achieved by the
student for the Physics examination. I did this so as to be able to compare the students’
performance in explanation-type questions and non-explanation-type questions. I added
space to record the student’s responses, which I used when the responses represented
a richly descriptive expression of a misconception. On completion of the classification-
grid I submitted the grid to my supervisor, who examined and refined it.
3.7.1.3 Preliminary classification
With the grid refined, I performed a preliminary classification of 100 scripts together with
two other coders. The coders are both suitably qualified, experienced science teachers.
According to Franzosi (n.d., p.187), it is “good practice to test the reliability of each
coding category by having different coders code the same material.” When a
88
misconception became evident in an explanation, it was labelled according to the type
of explanation offered. For example, a misconception in a mechanical explanation was
referred to as a mechanical misconception. This approach therefore provided a way by
which misconceptions in scientific explanations could be categorized. The student
responses in the exam scripts were then classified into the following categories:
• No misconception, where the student explanation was conceptually correct.
• Misconception, where the students explanation is inconsistent with the commonly
accepted scientific explanation.
• Inconclusive, where the response was marked incorrect, but it could not be
established that a misconception existed.
• No response, where the student did not attempt the question.
The category of “inconclusive” was not a part of the original classification, but I was
forced to include it after it became clear to me that many responses that were incorrect
lacked sufficient evidence to be coded as a misconception. I do not contend here that
students who produced these responses did not have a misconception inherent to their
explanation, but merely that there was a lack of evidence in the explanation for us to
infer that a misconception existed. Many cases that fell into this category suggested that
the students had either not read the question properly or that they did not understand
the question due to poor language skills or lack of knowledge on the specific subject
content. Student responses that were catergorised as “inconclusive” in terms of
misconceptions did not focus on what was demanded in the question. For example, in
answering question 5.3 students were expected to use Physics principles to explain
how the masses of the cars affect the risk of injury during a collision. The following
examples show how students neglected to consider the masses of the cars and instead
focused on another aspect in the question.
It is too dangerous for people who are inside the car because they will all have an accident that is
caused by the high speed of the cars.
89
Modern cars are designed to crumple partially on impact, and it decreases the dangers of risk in
the injury.
In the first example, the student refers to the speed of the cars, which despite being a
factor in the risk of injury, was not the focus of this question. In the second example, the
student refers to modern cars which crumple upon impact. Although this is correct, it
again represents a case where the student had missed the focus of the question.
As part of the preliminary classification we also recorded specific student responses that
expressed detailed misconceptions, commented on significant issues such as poor
language usage and misunderstanding of the question and recorded the marks
achieved by the students for each explanation-type question and for the Physics paper
as a whole. The preliminary classification helped to verify the reliability of the
classification process. Intercoder reliability was 86%. Where disagreement did exist it
was resolved through discussion.
During the preliminary classification we found five specific misconceptions that were
occurring frequently. Together with my supervisor, I decided to add them onto the
analysis grid in order to determine the exact frequency at which these misconceptions
were occurring in the sample provided. The final classification-grid is included as table
3.1, next:
90
Table 3.1: Final misconception classification-grid
Source: Compiled by researcher
Common
misconceptions
He
av
ier
car
-mo
re
imp
act
En
erg
y is
lost
R l
ess
wh
en
pa
ralle
l R
bu
rns
Sp
lit-r
ing
Vo
lta
ge
incr
ea
ses
Scr
ipt
nu
mb
er:
Stu
de
nt'
s to
tal
for
the
ex
pla
na
tio
n Q
's:
/32
Stu
de
nt'
s a
nsw
er
Stu
de
nt'
s m
ark
for
the
Ph
ysi
cs
pa
pe
r: /1
50
No misconception
Inconclusive misconception
Teleological :
Part of phenomenon
Tautological :
Back to question
Rational expl: Evidence
Practical expl: How to
Metaphysical: Supernatural
Mechanical:
Physical properties
Genetic : What not why
Functional explanation
Anthropomorphic :
Human attributes
Analogical explanation:
Familiar situation
Question totals 2
3
1
2
2
2
2
4
4
2
4
4
32
Students’ marks
Qu
est
ion
s
5.2
Wh
y m
ay
co
nse
rva
tio
n o
f p
no
t
be
va
lid?
5.3
Wh
y a
re p
ass
en
ge
rs in
a h
ea
vie
r
car
less
lik
ely
to
ge
t in
jure
d?
7.5
Wh
at
ha
pp
en
s to
Ek
th
at
is n
ot
con
ve
rte
d t
o e
lect
rica
l en
erg
y?
9.3
De
scri
be
dif
fra
ctio
n p
att
ern
9.4
Na
me
1 s
imila
rity
an
d 1
dif
fere
nce
ob
serv
ed
be
twe
en
sin
gle
an
d d
ou
ble
slit
pa
tte
rn
9.5
Will
pa
tte
rn b
e s
ee
n w
ith
a li
gh
t
bu
lb?
Re
aso
n?
10
.2
Is
B –
or
+?
Re
aso
n?
11
.2 P
or
Q b
ett
er
con
du
cto
r?
Exp
lain
.
12
.3 H
ow
wil
l V c
ha
ng
e if
R b
urn
s
ou
t/ R
ea
son
.
13
.1 T
yp
e o
f g
en
era
tor?
Re
aso
n.
14
.3 E
xpla
in w
hy
cu
t o
ff s
wit
ch is
imp
ort
an
t.
15
.3 I
nte
nsi
ty in
cre
ase
d.
Exp
lain
wh
at
ha
pp
en
s to
en
erg
y a
nd
no
. o
f
ph
oto
-e
To
tals
:
Co
mm
en
ts:
91
3.7.1.4 Further classification of student responses in the sample of exam
scripts
After the preliminary classification process and final refinements to the classification-
grid, I continued to fill in a classification-grid for each one of the 921 exam scripts. I
followed the same process of classification and recording as in the preliminary
classification, classifying each student response as a particular type of explanation. I
also continued to record specific student responses that represented misconceptions,
commented on significant issues as they became apparent and recorded the marks
achieved by each student. In addition, I recorded whether or not each student held any
of the five common misconceptions that I had added onto the classification-grid after the
preliminary classification process. The process of classification extended from July 2009
to December 2009. Examples of completed classification-grids are included as
appendix L.
3.7.2 Quantitative analysis of the exam-script data
The exams contained numeric data, such as marks allocated to specific questions and
marks achieved by individual students. Burton et al., (2008, p.146) explain the following:
Research reports that make effective use of both quantitative and qualitative data will often lead
with the quantitative evidence to provide an immediate point of impact as a ‘headline’ and then
follow it up and enrich the interpretation and analysis through the introduction of the qualitative
sources.
The purpose of the quantitative analysis was to indicate the frequency of
misconceptions, the frequency of various explanation-types and the performance of
students in explanation-type questions, thereby highlighting the need to delve further
into the nature of these misconceptions and explanation-types.
In order to calculate the frequency of misconceptions, I made use of the data on the
classification-grids which had been filled in for each student during the data-collection
phase of this study. I used the data to calculate the following proportions: percentage of
misconceptions revealed in explanations, percentage of responses with no
92
misconception, percentage of misconceptions revealed for each explanation-type,
percentage of no responses and percentage of responses classified as inconclusive
with regard to misconceptions.
In order to determine the performance of students in explanation-type questions I
calculated the average percentage achieved for explanation-type questions and the
average achieved for non-explanation-type questions. I also calculated the percentage
of explanation-type questions and non-explanation-type questions present in the
examination paper. I did this in order to explore the possible emphasis on exemplar-
type calculations and rote-learning as the majority of non-explanation-type questions fall
into these categories.
3.7.3 Computer-Assisted Qualitative Data Analysis
Both the exam scripts and interview transcriptions contain information-rich text. I typed
out several information-rich student responses which I extracted from the exam scripts. I
copied these responses and the interview transcriptions onto documents called primary
documents, using the computer software Atlas.ti. I used the software to systematise the
data, while understanding that it remains the researcher’s task to code the data and
organise the analysis (Smit & Lautenbach, 2009).
When working with qualitative data there are many possible ways to process data into
“patterns of meaning”, however it is crucial to fit the method of analysis to the research
design (Henning et al., 2004, p.102). Hence I decided to select qualitative content
analysis which involves seeking emerging patterns. In order to find patterns I read
through all of the interview transcripts, thereby attaining a comprehensive idea of the
data. As I read through the data a second time, I started to identify and highlight
meaningful words or phrases that captured common misconceptions and their
relationship with explanation-types. I extracted these meaningful words and phrases
from the data and reduced them to codes which convey the essence of the data. I
constructed 50 codes and organised them with the assistance of Atlas.ti, as indicated in
table 3.2:
93
Table 3.2: Analysis codes
HU: Student Misconceptions in grade 12 Physics.hpr1 File: [D:\Celeste (F)\Celeste\STUDIES\Masters\atlasti\Student Misconceptions in grade 12 Physics.hpr1.hpr6] Edited by: Super Date/Time: 10/07/02 08:14:20 AM
Application of theory is problematic Assessment as a barrier to diagnosing and remedying misconceptions Calculation questions are more straightforward Confused: Between internal and external R Confused: conservation of Ek vs p Confused: Generators vs motors Confused: difference btw laser and light bulb, coherent Confused: mass and weight, using interchangeably Confused: series and parallel Construction of a functional misconception Construction of a functional misconception regarding resistance Construction of a genetic misconception Construction of a genetic misconception: Why current increases when adding appliances in multi-plug Construction of a genetic Misconception: voltage across parallel resistors Construction of a mechanical misconception Construction of a metaphysical misconception Construction of a practical misconception Construction of a rational misconception Construction of a tautological misconception Construction of a teleological misconception Construction of an analogical misconception Construction of an anthropomorphic misconception Electricity misconceptions Experiments are important Frequent misconception: A heavier car exerts a greater force on a lighter car during a collision Frequent misconception: Cut-off switch increases V, safe and saves
Frequent misconception: Energy is lost Frequent misconception: R decreases when a parallel resistor is removed Frequent misconception: Split rings Hidden construct: Teleological, inconclusive and no response Incomplete constructions: Mechanical, Genetic, Functional, Tautological, Metaphysical and Practical Inconclusive misconception Language as a source of misconceptions Language problem Students answer questions without true understanding Students don't understand what is expected in explain questions Students forget electricity done in grade 11 and examined in grade 12 Mathematical literacy Misconception: Conductivity depends on both I and V, not only I Misconception: matter is created Misconception: momentum Misconceptions influences and is influenced by class atmosphere Newton's third law doesn't make application sense to the student No training or meetings on misconceptions Remedies for misconceptions_1 Simple construct: Anthropomorphic and analogical Sources of misconceptions Struggles with the concept of potential difference Teach principles without revising basic principles Write it exactly like in the book
Source: Compiled by researcher
Next, I allocated codes to the data that matched the themes in the data, thereby
breaking-down and conceptualising the data into themes (Strauss & Corbin, 1990), this
process is known as open coding (Henning et al., 2004). The following are examples of
the open coding performed in this study: The code “Energy is lost” was attached to the
data “some of the energy is lost through sound”, the code “Mechanical explanation” was
attached to the data “Because it’s mass is greater.”
94
I also used “In-Vivo” coding (Atlas.ti), where the selected text itself becomes the code.
For example, I selected the data: “Like I want to say something and I try to write it
exactly like in the book, and if I forget I get blank and then just move onto the next
question, and think I will come back to it” and coded it as “Write it exactly like in the
book.”
The next step was to reconstruct the data, by clustering interrelated codes together. For
example: the codes “Application of theory is problematic”, “Calculation questions are
more straightforward”, “Language problem”, “Students answer questions without true
understanding”, “Students don't understand what is expected in explain questions”,
“Students forget electricity done in grade 11 and examined in grade 12” and “Write it
exactly like in the book”, were clustered together to form the family: “Assessment as a
barrier to diagnosing and remedying misconceptions.” These codes which had been
attached to both exam-script data and interview-data are all related to the relationship
between assessment and misconceptions which also emerged in the literature review.
Another example is the clustering of the codes: “Construction of a tautological
misconception”, “Frequent misconception: Energy is lost”, “Inconclusive misconception”
and “Misconception: matter is created” to form the family: “Hidden constructions:
Tautological, inconclusive and no response”. These codes all relate to the hidden nature
of misconceptions, which makes their diagnoses complex and calls for more emphasis
on assessment and teaching strategies that promote conceptual understanding and
reconstruction of misconceptions.
I repeated the clustering process until I had narrowed down the clusters, also known as
families, to seven main themes or findings. These families, which supply valuable
information regarding common misconceptions and their relation to explanations, have
been extracted using the computer software, and are listed in table 3.3:
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Table 3.3: Code families HU: Student Misconceptions in grade 12 Physics.hpr1 File: [D:\Celeste (F)\Celeste\STUDIES\Masters\atlasti\ Student Misconceptions in grade 12 Physics.hpr1.hpr6]
Edited by:Super Date/Time:11/09/17 12:49:43 PM ______________________________________________________________________ Code Family: Assessment as a barrier to diagnosing and remedying misconceptions Created: 10/07/01 10:44:49 AM (Super) Codes (7): [Application of theory is problematic] [Calculation questions are more straightforward] [Language problem] [ Students answer questions without true understanding] [ Students don't understand what is expected in explain questions] [ Students forget electricity done in grade 11 and examined in grade 12] [Write it exactly like in the book] Quotation(s): 39 ______________________________________________________________________ Code Family: Hidden constructions: Tautological, inconclusive and no response Created: 10/07/01 10:43:06 AM (Super) Codes (4): [Construction of a tautological misconception] [Frequent misconception: Energy is lost] [Inconclusive misconception] [Misconception: matter is created] Quotation(s): 14 ______________________________________________________________________ Code Family: Incomplete constructions:Mechanical, Genetic, Functional, Teleological and Practical Created: 10/06/30 05:24:35 PM (Super) Codes (20): [Confused: Between internal and external R] [Confused: conservation of Ek vs p] [Confused: Generators vs motors] [Confused: series and parallel] [Construction of a functional misconception] [Construction of a functional misconception regarding resistance] [Construction of a genetic misconception] [Construction of a genetic misconception: Why current increases when adding appliances in multi-plug] [Construction of a genetic Misconception: voltage across parallel resistors] [Construction of a mechanical misconception] [Construction of a practical misconception] [Construction of a teleological misconception] [Frequent misconception: A heavier car exerts a greater force on a lighter car during a collision] [Frequent misconception: Cut-off switch increases V, safe and saves] [Frequent misconception: R decreases when a parallel resistor is removed] [Frequent misconception: Split rings] [Incomplete constructions: Mechanical, Genetic, Functional, Tautological, Metaphysical and Practical] [Misconception: Conductivity depends on both I and V, not only I] [Misconception: momentum] [Struggles with the concept of potential difference] Quotation(s): 46 ______________________________________________________________________
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The computer software enabled me to code the data and cluster the 50 codes more
efficiently as it is able to pull together data with common codes.
Code Family: More complex constructions: Rational misconceptions Created: 10/07/01 11:33:32 AM (Super) Codes (3): [Construction of a rational misconception] [Frequent misconception: A heavier car exerts a greater force on a lighter car during a collision] [Frequent misconception: R decreases when a parallel resistor is removed] Quotation(s): 20 ______________________________________________________________________ Code Family: Relationship between language and misconceptions Created: 10/07/01 10:50:18 AM (Super) Codes (9): [Application of theory is problematic] [Confused: difference btw laser and light bulb, coherent] [Confused: mass and weight, using interchangeably] [Frequent misconception: Energy is lost] [Language problem] [Misconception: matter is created] [Newton's third law doesn't make application sense to the student] [Struggles with the concept of potential difference] [Write it exactly like in the book] Quotation(s): 52 ______________________________________________________________________ Code Family: Remedies for misconceptions Created: 10/07/01 10:54:55 AM (Super) Codes (7): [Experiments are important] [Language problem] [ Students don't understand what is expected in explain questions] [Mathematical literacy] [No training or meetings on misconceptions] [Sources of misconceptions] [Teach principles without revising basic principles] Quotation(s): 34 ______________________________________________________________________ Code Family: Simple constructions: Anthropomorphic, analogical and metaphysical Created: 10/07/01 11:42:43 AM (Super) Codes (3): [Construction of a metaphysical misconception] [Construction of an analogical misconception] [Construction of an anthropomorphic misconception] Quotation(s): 1
Source: Compiled by researcher
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3.8 CLEANING UP THE CONSTRUCTION SITE – DATA STORAGE
The data have been stored in such a manner as to ensure the confidentiality of
participants. It will be kept under lock and key for 2 years after the study, after which it
will be destroyed.
3.9 CONCLUSION
In this chapter I have discussed the processes of designing my qualitative content
analysis based on the foundations of social constructivism and the logics of
contextualisation, discovery and diachronicity. I then discussed the collection of data by
means of identifying the misconceptions in both the exam scripts and discursively
oriented interviews. Lastly, I discussed the data analysing methodologies of coding and
clustering as assisted by computer software. Now it is time to move to the next chapter
where I will discuss the results that I have found emerging from the data.
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CHAPTER 4
PRESENTATION, DISCUSSION AND INTERPRETATION OF THE RESEARCH
RESULTS
4.1 INTRODUCTION
This chapter commences with a presentation of data regarding the performance of
students in explanation-type questions as opposed to non-explanation-type questions.
Next, the distribution of explanation and non-explanation type questions, in the 2008
NSC Physics examination, is presented. The chapter continues with a presentation of
the frequency of the misconception-types that were generated in this study. These
misconception-types were generated according to the Dagher and Cossman (1992)
explanation-types. These misconception-types are also discussed and illustrated using
examples from the exam-script and interview data. In addition, the frequency of five
common misconceptions is presented and these five common misconceptions together
with other misconceptions identified through this study are discussed. The chapter ends
with an interpretation of what the misconception-types reveal in terms of possible
sources of misconceptions.
4.2 STUDENT PERFORMANCE IN EXPLANATION-TYPE QUESTIONS
The aims of this study are to identify student misconceptions as revealed in student
explanations and to classify these misconceptions according to the types of
explanations in which they are revealed. I also aimed to determine how students
perform in explanation-type questions. According to Bryce and MacMillan (2009)
students perform poorly in explanation-type questions. In this section I present data on
the performance of students in explanation-type questions. I have also included data on
the performance of students in non-explanation-type questions, as the comparison
between the performance of students in explanation and in non-explanation-type
questions highlights the poor performance of students in explanation-type questions.
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On analysing the exam scripts I found that the sample of 921 students achieved an
average of 17, 4% for the explanation-type questions, and an average of 25, 8% for the
non-explanation-type questions, and an overall average of 24% for the Physics exam in
its entirety. A graphical presentation of these results follows in figure 4.1:
Figure 4.1: A bar graph of the performance of a sample of students
Source: Compiled by researcher
As can be seen by the above results, the poor performance of students in explanation-
type questions decreases the overall performance of the sample by 1,8%. Students
performed 8,4% worse in explanation-type questions than in non-explanation-type
questions.
The poor performance of students in explanation-type questions may be attributed in
part to the fact that explanation-type questions expose students’ understanding and
misconceptions (Graesser et al., 1996; Sevian & Gonsalves, 2008). On the other hand,
students’ responses to the type of non-explanation-type question that can be mastered
by rote learning do not effectively reveal their true level of understanding (Mintzes et al.,
2001). According to Harrison et al., (1999), students are able to treat exemplar-type
calculation questions as simple algorithms. These exemplar-type calculation questions
are found as examples and in exercises within textbooks. Students study these
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examples and practice them for homework. This allows students to complete these
types of calculations successfully in assessments without revealing their
misconceptions and without changing their incorrect conceptions. The following
comment was made by one of the student interviewees regarding exemplar-type
calculation questions: “That’s because it’s straight forward, you know the formula and
you just do it.”
Students may also perform poorly in explanation-type questions because they are not
aware of what is expected from them in the answering of these types of questions. This
problem may arise due to the overemphasis on non-explanation-type questions and is
discussed in the next section.
4.3 DISTRIBUTION OF EXPLANATION AND NON-EXPLANATION QUESTIONS
In this section I present the distribution of explanation-type questions as opposed to
non-explanation-type questions in the 2008 NSC Physics examination paper. Of the 150
marks allocated to the Physics exam, 32 marks (21%) were allocated to explanation-
type questions and a substantially larger share of 118 marks (79%) was allocated to the
non-explanation-type questions. The non-explanation-type questions consisted largely
of selected response questions and exemplar-type calculations. The selected response
questions consisted of multiple-choice and true or false questions. The distribution of
question-types is illustrated in figure 4.2:
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Figure 4.2: A pie chart of the question-types in the NSC 2008 Physics exam
Source: Compiled by researcher
The data illustrate the emphasis that examiners place on non-explanation-type
questions. This emphasis focuses the attention of teachers and students on non-
explanation-type questions. Most non-explanation-type questions can be mastered by
rote learning. Even the calculation-type questions found in school exams rarely differ
from the examples found in textbooks and in previous exams. This focus leads to very
little time being spent on the development of students’ conceptual understanding. It is
important that examiners do not merely change the emphasis from non-explanation-
type to explanation-type questions without aiming to promote conceptual learning, as
this may lead to more rote learning.
4.4 DESCRIBING THE DIFFERENT TYPES OF MISCONCEPTIONS AND THEIR
FREQUENCY
Each of the 11052 student exam-script responses [twelve responses for each student in
the sample of 921 students] was coded into one of the following categories:
• Misconception, where the student’s explanation is inconsistent with the
commonly accepted scientific explanation.
• No misconception, where the student explanation was conceptually correct.
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• Inconclusive, where the response was marked incorrect, but it could not be
established that a misconception existed.
• No response, where the student did not attempt the question
As mentioned in chapter 3 the category of “inconclusive” was not a part of the original
classification, but because many responses lacked sufficient evidence for them to be
coded as misconceptions I was forced to include the category of “inconclusive”.
Each exam-script response revealing a misconception was then classified according to
the Dagher and Cossman (1992) explanation-types. Classifying each response as a
specific type of explanation enabled me to diagnose the misconception that was
inherent to a type of explanation. For example, where a student advanced a mechanical
explanation I was able to focus on his/her conception of the relationship between a
physical property of an object and its behaviour and then explore this relationship for a
misconception. Such responses were then classified as a mechanical misconception.
The data regarding the occurrence of various types of misconceptions are tabulated in
table 4.1 and illustrated in figure 4.3:
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The most prevalent misconceptions were located in genetic and mechanical
explanations. Both table 4.1 and figure 4.3 indicate that these two types of explanations
together yielded 77,7% of the identified misconceptions. In the genetic explanations
students explained what happened instead of why it happened. In the mechanical
explanations students explained the phenomenon by supplying the physical properties
of an object as the only evidence.
In total, 11,6% of the identified misconceptions were classified as functional
explanations. The majority of these misconceptions occurred in question 14.3 where
students were asked to explain the importance of the cut-off switch in a multi-plug.
Students have various misconceptions regarding the function of the cut-off switch.
These include the misconceptions that it lowers the voltage when the voltage gets too
much, that it saves electricity by switching off when electricity usage is too high, that it
Types of Responses Number of responses
Percentage of responses (%)
Percentage of misconceptions (%)
Misconception
Analogical 0 0 0 Anthropomorphic 4 0.04 0.1 Functional 352 3.2 11.6 Genetic 1238 11.2 40.9 Mechanical 1116 10.1 36.8 Metaphysical 0 0 0 Practical 7 0.06 0.2 Rational 151 1.3 5 Tautological 117 1.1 3.9 Teleological 46 0.4 1.5 Sub-total 3031 27.4 100
No misconception 1285 11.6
Inconclusive 5787 52.4
No response 949 8.6
Total 11052 100
Table 4.1: Types of responses identified in a sample of student exam scripts
Source: Compiled by researcher
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can prevent a person from getting shocked, that it works like a normal switch which can
be switched off, and that it can split the voltage between various appliances. These
misconceptions may have occured because the function of a cut-off switch is not
directly addressed in the syllabus.
Figure 4.3: A bar graph of the frequency of misconception-types in a sample of
student exam scripts
Source: Compiled by researcher
Figure 4.3 illustrates that a total of 5% of the identified misconceptions were classified
as rational explanations. Students constructing these explanations attempted to apply
laws of Physics to explain phenomena, but did so incorrectly. When attempting a
rational explanation students often only consider two variables in an equation as if the
third variable automatically remains constant, which it often doesn't. For example,
students answer that the heavier car has more momentum because p=mv, thereby
neglecting the velocity variable.
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A total of 3,9% of the identified misconceptions were classified as tautological
explanations. In these explanations students answered the question by circling back to
the question. An example of such an explanation occurred in response to question 5.3.
In this question, students were asked to use principles of Physics to explain why a traffic
officer would be correct in stating that the risk of injury for passengers in a heavier car
would be less than in a lighter car. In response, a student wrote: “It is because he
mentions that for cars involved in a head-on collision, the risk of injury for passengers in
a heavier car would be less than for passengers in a lighter car."
In total, 1,5% of the identified misconceptions were classified as teleological
explanations. In these explanations students incorrectly explained an occurrence as
being part of a phenomenon. For example, in question 5.2 students were asked why the
conservation of momentum may not be valid in a specific collision. Students then
answered with the misconception that momentum was not conserved because the
collision was inelastic or elastic. Olivier (n.d., a, p.70) explains that “Inelastic collisions
are collisions where kinetic energy is not conserved.”
Very few misconceptions were classified as either practical or anthropomorphic
explanations, only 0,3% collectively. In practical explanations, students explain how
things should be done instead of explaining why things happen or are important. An
example of a misconception that was exposed in a practical explanation is that cut-off
switches should be put off. Cut-off switches are trip-switches and cannot be put off to
save electricity. This misconception is illustrated in the following student responses: “It
is important to cut off appliances that are not in use. It's more expensive because you
are paying for electricity supplied to appliances not in use" and "The cut of switch is
important because when the multi-plug is over loaded, switch on the cut-off switch
quick." It is clear from these responses that students are incorrectly explaining what
should be done with cut-off switches instead of explaining why they are important. The
few students who constructed anthropomorphic explanations seemed to attribute
human attributes to things as a manner of speech rather than actually believing that an
object has those human attributes. Students and teachers do this in an attempt to relate
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better with the abstract nature of scientific phenomena (Dagher & Cossman, 1992).
Treagust and Harrison (2000, p.1165) argue that anthropomorphisms are “acceptable
elements of effective pedagogical content explanations because teachers’ pedagogical
content knowledge is neither pure science nor is it intended to be.” Anthropomorphisms
are often used in order to bridge the gap between scientific and everyday language,
because students often do not know the correct scientific terms. The following student
responses illustrate the construction of anthropomorphic explanations: "So that
electrons would get time to rest, when switch it on they perform a good work" and "If the
resistor burns out the voltmeter will decrease because the voltmeter is helping out the
resistor.” In these explanations the one student attributed the human action of resting to
inanimate electrons instead of explaining that the electric current stops flowing and
another student described a voltmeter as being able to help out a resistor.
No misconceptions were identified in analogical and metaphysical explanations. This is
likely due to the fact that teachers only use analogies in certain sections of work where
they are acquainted with analogies that correspond to the content, and the content that
was assessed in the exam that was analysed did not lend itself readily to the use of
analogies. Nevertheless, it is important for teachers to be careful when using analogies.
Teachers must make sure that students are aware of not only the similarities between
the analogy and the target, but also the differences between them. Thiele and Treagust
(1991, p.6) warn that “Teachers should not assume that students are capable of
effecting correct analogical transfer but, rather, should provide explicit instruction on
how to use analogies and provide opportunity for considerable classroom discussion on
the subject.” Treagust and Harrison (2000, p.1163) also advise that “students need
guidance in mapping the shared and unshared attributes if understanding is to be
maximized.” Students also did not refer to any supernatural causes in their
explanations. Dagher and Cossman (1992, p.369) classify metaphysical explanations
as “spurious”. Spurious or “counterfeit” explanations (Gilbert et al., 1998b, p.191) are
formulated in such a manner that they cannot be proven as true or false, as opposed to
genuine or authentic explanations which are falsifiable (Trusted as quoted by Dagher &
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Cossman, 1992). Gilbert et al. (1998b, p.191) warn that spurious explanations may be
seen as “legitimate in certain cultural contexts.”
4.5 FIVE COMMON MISCONCEPTIONS
In the sample of 921 scripts, five specific misconceptions occurred frequently. I decided
to focus my subsequent analysis on these misconceptions.
4.5.1 The frequency of five common misconceptions
The frequency of these five misconceptions is indicated in figure 4.4:
Figure 4.4: A bar graph of the frequency of common misconceptions as
revealed in a sample of student exam scripts
Source: Compiled by researcher
The graph shows that almost a quarter of the student sample held the most frequent
misconception revealed in this study, the misconception that a heavier car exerts more
impact during a collision.
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4.5.2 The nature of five common misconceptions
In this section the nature of the five common misconceptions is discussed. During the
discussion I will draw upon data collected from both the exam-script responses and
student interviews. I will also refer to the explanation-type in which the misconception
was revealed because it reveals information regarding the nature of the misconception.
In order to determine the explanation-types in which the common misconceptions are
revealed, I studied the misconception classification-grids, which were completed for
each exam script in the sample. I counted the number of responses classified according
to each explanation-type for each separate question in the 2008 NSC Physics
examination. These results are shown in table 4.2:
Table 4.2: Types of student responses classified per question
Source: Compiled by researcher
Qu
es
tio
n N
um
ber
No
mis
co
nc
ep
tio
n
Inco
nc
lusiv
e
No
re
sp
on
se
Mis
co
nc
ep
tio
ns
Types of explanations revealing misconceptions
Mech
an
ica
l
Ge
ne
tic
Fu
nctio
nal
Ra
tio
nal
Ta
uto
logic
al
Tele
olo
gic
al
Pra
ctica
l
An
thro
pom
orp
hic
An
alo
gic
al
Meta
ph
ysic
al
5.2 48 195 30 648 267 332 4 5 15 24 2 0 0 0
5.3 43 177 31 670 396 175 0 71 16 12 0 0 0 0
7.5 74 610 99 138 1 126 1 5 4 1 0 0 0 0
9.3 123 710 75 13 2 1 1 1 6 2 0 0 0 0
9.4 109 695 80 37 27 3 0 0 6 1 0 0 0 0
9.5 125 663 77 56 24 25 1 2 2 1 1 0 0 0
10.2 263 537 24 97 7 78 5 1 4 1 1 0 0 0
11.2 190 463 14 255 181 50 2 8 13 0 0 0 0 0
12.3 13 435 75 394 149 154 9 47 31 2 0 2 0 0
13.1 191 610 45 79 4 69 2 2 0 1 1 0 0 0
14.3 19 312 119 473 19 114 324 8 3 1 2 2 0 0
15.3 87 381 280 171 39 111 3 1 17 0 0 0 0 0
Total 1285 5787 949 3031 1116 1238 352 151 117 46 7 4 0 0
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4.5.2.1 First common misconception: heavier cars exert more impact on lighter
cars during a collision
The first common misconception identified in this study appeared in student responses
to question 5.3 of the Physics exam. In question 5.3 students were asked to use
principles of Physics to explain why the risk of injury for passengers in a heavier car
would be less than for passengers in a lighter car. Question 5.3 is shown in figure 4.5:
Figure 4.5: An examination question on the collision between two cars
Source: DOE – November 2008 NSC grade 12 Physical Sciences (P1)
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A total of 670 misconceptions were identified for this question from the sample of 921
student responses. The majority (59%) of these misconceptions were in student
explanations that were coded as mechanical. In these explanations, students had a
misconception about how a physical property of an object explained its behaviour or a
phenomenon related to it.
A common misconception revealed in the students’ mechanical explanations was that
during the interaction between two objects the heavier object exerts a greater force on
the lighter object. This misconception was held by 219 students in the sample, and
represents 33% of the 670 misconceptions exposed by this question. Students who
constructed a mechanical explanation containing this misconception, focussed on the
physical property of mass to explain the interaction between two objects. The following
exam script response illustrates this misconception and the student’s focus on the
physical properties of the objects: “A lighter car will easily get crushed due to the mass
of the heavier. The heavier the mass, the greater the force.” This misconception was not
only evident in the exam-script responses but also in the pre-interview test and in the
interview data, as illustrated by the following responses by student interviewee one and
four respectively:
The heavier car will exert a much higher force than the lighter car.
The weight of the car influences like the force that the car exerts, so if a car is moving at a certain
speed, and then the lighter one is also moving at a certain speed too, then the heavier car tries to
brake, it’s going to take longer for it to brake, because of all of the weight on it than the smaller
one, so then the heavier one is going to exert more force than the smaller one, That’s why the
smaller one has more risk of getting injured than the heavier one.
The students’ focus on the mass of the cars was not the problem. The question required
students to consider the mass and then to discuss the relationship between mass and
acceleration. However, students exposed their misconceptions about mass by
constructing a mechanical explanation which focuses only on mass. The quotations
above also illustrate the misconception that mass, weight and force are similar
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properties of matter. This misconception causes students to use the terms
interchangeably as if they have the same meaning.
The misconception about heavier objects exerting more force contradicts Newton’s third
law and prevents students from properly understanding it. Students may even construct
explanations with both Newton’s third law and the misconception about heavier objects
alongside one another, as illustrated by the following exam-script responses:
Using Newton's third law the car with a heavier mass will exert a greater force on the car with a
lighter mass.
This is Newton’s third law – when object A exerts force on object B, object B will exert equal but
opposite force of object B. This is applied here because when a lighter car collides with a heavier
car, they will be greater opposite force exerted on a lighter car, but will result in injuries to the
passengers in a lighter car, during head-on collision.
During an interview a student expressed his experience of Newton’s third law as
follows:
Student 3: I heard an example once where they said that when a mosquito collides into a
car, the mosquito experiences the same force as the car experiences from the
mosquito.
Researcher: Do you believe that?
Student 3: I don’t know what they mean, that the force will be the same, because like, like to
me it doesn’t make much sense.
Yet another student interviewee, student six, explained that Newton’s third law cannot
be applied to a head-on collision: “But it can’t be because it isn’t closed.” This student
incorrectly applied the conditions for conservation of momentum to Newton’s third law,
which has no conditions.
Students did not only focus on the masses of the cars, in their mechanical explanations,
but also on the strength of the car materials. The following two exam-script responses
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show how students focused on the strength of the materials from which the cars are
made:
The passengers in a lighter car are more likely to get injured because it is made of weaker
material.
The passenger in a heavier car has weight and the material of the car has a higher mass and its
velocity is also high which means the car is very strong, as for the lighter car it is not strong.
Instead of focussing on the strength of materials, students ought to have explained the
relationship between the mass of the car and the change in velocity of the car by
referring to Newton’s Second Law of motion. However, by constructing a mechanical
explanation based on the strength of materials, students exposed the misconception
that stronger materials exert more force. The following interview data also illustrates this
misconception:
Researcher: You wrote: “the driver of the truck will take less impact because of its size and
mass, and the truck will make the car move in the same direction. Tell me more
about why you think the truck will take less impact because of its mass?
Student 2: I think it is because of the material which it is made of, it’s it’s, a car it’s more like
a, I don’t want to say plastic, because there are some parts, like it’s made out of
plastic, more than the truck, you know, it’s not plastic, plastic, but you know
that…, I don’t know that material it’s made off; and the truck has more weight,
you know there’s more stuff put on it and because of the material as well, so
when it collides it will move um the car… the same direction as the truck was
moving.
Although weaker materials may experience more bending and damage as a result of
force, they do not exert less force than stronger materials. Also, the fact that a weaker
material bends and breaks more, means that the contact time of the collision increases,
thereby decreasing the force of impact on both of the cars.
Students also constructed genetic explanations containing misconceptions. Genetic
explanations accounted for 26% of misconceptions for this question. In the genetic
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explanations that were offered, students focused on describing what happens instead of
providing scientific evidence regarding why the event happens. By focussing on what
happened, students exposed their misconceptions regarding the interaction between
two objects. This was evident in the following exam-script responses:
The heavier car overpowers the lighter car in the collision. The lighter car will be squashed but
the heavier car will be less squashed than the lighter car.
The heavy car is much more powerful and pushes the lighter car with a bigger force. It causes
more damage to it and injures the passengers.
In both responses students appear to have a naïve understanding of the relationship
between the mass of the car, its horsepower and the force it exerts upon impact. Firstly,
the above responses suggest that the car with larger mass is more powerful. This is
incorrect as the power of a body is defined as the rate at which that body does work
(Heyns et al., 1999). Although power is influenced by mass, because the work done on
an object during horizontal motion is equal to the change in the kinetic energy of the
object – ∆Ek = ½ m (v2 - u2), (Olivier, n.d., a), mass is not the only variable which power
depends on. Furthermore, students infer that if a body is more powerful it will exert a
larger force upon impact than a body less powerful. This again is incorrect, as the cars
exert equal but opposite forces on each other when colliding.
To a lesser extent rational explanations containing misconceptions were evident in
student responses to this question (11%). Some of the students who constructed these
rational explanations held the same common misconception about heavier objects
exerting a greater force. However, they provided a rationale, based on Newton’s
Second Law, for their argument that heavier cars exert a greater force on lighter cars.
For example, a student wrote that:
F=ma. When mass is heavy then F increases or F is more. When mass is light then force is not
that much. A heavy car will exert a greater force on the lighter car than it (lighter car) would on
heavier car and the passengers of the lighter have higher risk of injury.
114
The above response clearly reveals that the student does not realise that F=ma gives
the force needed to accelerate the mass m; it does not give the force exerted by the
mass m on another object. In addition, the student forgets to consider acceleration, the
other variable in Newton’s second law.
Another example of a rational explanation with the same misconception is given in the
following exam-script response:
Fres = ∆p/∆t , as the time for the lighter car to be crashed will be shorter than that of the heavier
car, the force (resultant force) acting on the car will increase quickly and cause more damage
than in a heavier car.
In the above response the student uses Newton’s second law to calculate the force
acting on the lighter car, however, the student makes a mistake. The mistake is that the
student argues that the contact time of the collision is smaller for the lighter car when it
is actually equal to the contact time for the heavier car.
This misconception that heavier cars are more powerful and exert more force on one
another has been reported on in previous studies (Bayraktar, 2009; Eshach, 2010) and
is a result of students viewing the interaction between objects as a struggle where
victory belongs to the stronger, bigger, heavier, or more active object. Students also
construct this misconception because they ascribe the incorrect ontological category to
force, and see it as a property of matter (Galili, as cited by Moore & Harrison, 2004),
much like mass, instead of seeing it as an interaction between two objects (Shymansky
et al., 1997).
4.5.2.2 Second common misconception: total external resistance decreases
when an external resistor connected in parallel is removed
Responses to question 12.3 revealed 394 misconceptions and this represented 13% of
all misconceptions identified. Question 12.3 is shown in figure 4.6 and referred to a
combination of resistors.
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Figure 4.6: An examination question on a circuit diagram of three external resistors
Source: DOE – November 2008 NSC grade 12 Physical Sciences (P1)
Question 12.3 demanded an explanation for what would happen to the voltmeter
reading should one of the resistors in the parallel combination burn out. The correct
answer to this question is that due to an increase in the external resistance, the current
strength decreases, resulting in a decrease in the internal voltage and an increase in
the voltmeter reading. Fifteen percent of the students in the sample held the common
misconception that the total resistance decreases when the one resistor in parallel
burns out.
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Many students offered genetic explanations containing misconceptions for this question;
39% of the misconceptions identified in this question were exposed in genetic
explanations. Students who constructed genetic explanations offered a variety of
incorrect conceptions as to what would happen when one of the resistors burnt out
without explaining why it would affect the voltmeter reading. The following exam-script
responses are genetic explanations which illustrate the common misconception that the
resistance decreases when a resistor connected in parallel is removed:
Less voltage would be needed since the resistance has dropped.
The reading will increase because more current will pass through without having to go via a
resistor.
The reading at voltmeter v will register a high voltage because the resistor which stops current
from passing through will have burnt out allowing a lot of current to pass.
Students also constructed mechanical explanations for question 12.3; in total 34% of
the misconceptions identified in this question were exposed in mechanical explanations.
Students who constructed mechanical explanations for this question focused primarily
on the resistance of the circuit, thereby exposing the misconception that the total
resistance decreases when a resistor connected in parallel is removed from a circuit.
Examples of such mechanical explanations are given in the following exam-script
responses:
The voltmeter reading will increase, because there is far less resistance within the circuit.
When resistor R is burn out the resistance changes to 13, 5 ohms. Voltmeter reading changes as
there is now less resistance.
Voltmeter it will be more because the less the resistance the higher the voltage.
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Rational explanations which exposed misconceptions constituted 12% of explanations
for this question. Students who constructed rational explanations that revealed,
misconceptions, applied Ohms’ law to determine the change in the voltmeter reading.
The following exam-script responses illustrate such a rational explanation:
If resistor R burns out, the voltage reading will increase. This is because R will increase as there
is no longer parallel resistance. Since V=IR if R increases then the total voltage will also increase
as they are directly proportional.
It will increase because potential difference is directly proportional to resistance.
The above responses are incorrect because although potential difference (V) is directly
proportional to resistance (R), it also depends on the current strength (I) which has
decreased in the situation sketched in this circuit. Also, the students have only
considered the changes in one part of the circuit instead of considering the circuit as a
whole. Cheng and Shipstone (2003, p.193) also found in their study that students tend
to “focus on what happens at only one point in the circuit and forget that they are
dealing with a complex interacting system.”
Four out of the ten students who were interviewed also held the misconception that
resistance decreases when a resistor connected in parallel burns out. The following
excerpt from a student interview further illustrates this misconception:
Researcher: So first tell me if that one burns out, why will there be less resistance in the
circuit?
Student 9: Because there’s one less resistor (smile).
4.5.2.3 Third common misconception: energy is lost
Question 7.5 referred to a hydro-electric power plant where water is funnelled down a
vertical shaft to a turbine below. Question 7.5 is shown in figure 4.7:
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Figure 4.7: An examination question on a hydro-electric power plant
Source: DOE – November 2008 NSC grade 12 Physical Sciences (P1)
In this question, students were required to explain what happens to the 15% of kinetic
energy that is not converted to electrical energy. The question required a genetic
explanation, because students were expected to state what happens to the kinetic
energy. In total, 13% of the students in the sample incorrectly responded that the
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energy was lost. In the genetic explanations advanced, 126 misconceptions were
identified. This represented 91% of all misconceptions for this question.
Examples of exam-script responses which illustrate this misconception, as revealed in a
genetic explanation, follow:
The 15% of kinetic energy is being lost.
Energy is lost through friction.
Energy is lost as the water falls on the turbine.
In the genetic explanations above, the students focused on what happened to the
energy, thereby exposing the misconception that energy is lost.
Students also constructed this misconception in the interviews. The following interview
dialogue occured when I asked a student to clarify a previous statement that she had
made concerning energy being lost:
Researcher: So you wrote that: “the other 15% is lost through other things such as heat,
movement, sound, etc.” Explain to me more about what you mean when you say
the energy is “lost”.
Student 10: ... the reason I came up with the fact, it could evaporate, it could be lost through
heat, vibrations, it could be lost through a lot of things ...
The above excerpt reflects that this student holds the notion that where the energy is
not being transferred to do work, it is “wasted” or “used up”. Scott et al. (2007, p.49)
explain that since the “concept of energy is used often in everyday contexts and in
everyday social language it is normal to make comments such as ‘I’ve run out of
energy’”. The scientific idea that energy is not used up appears to be far-fetched in
relation to everyday ways of thinking and speaking. Another student interviewee,
student three, confirmed that it is difficult to understand that energy is not lost by stating
the following:
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So in all essence it is lost, but the energy still is there it just isn’t in your possession, … they try
and steer us away from the term that it is lost, they try to tell us that it is not lost, it is just
converted and so forth, but for me to use, like, layman’s terms and to explain the science behind
it, to understand it better, I try to explain it in things that are easy to understand, like lost and not
converted.
In the above excerpt the student explains that the energy is still there but that it just isn’t
in your possession and that he prefers to explain things using words that are easy to
understand. This comment may illustrate that students which claim that “energy is lost”
do not necessarily hold a misconception regarding the conservation of energy but that
they may just use the phrase as a figure of speech. According to Harrison at al. (1999,
p.68) it is not uncommon for students to struggle with “adopting scientific understanding
and its associated language.” This is especially the case with scientific terminology such
as “energy” which is used differently in everyday language.
4.5.2.4 Fourth common misconception: a split-ring is found in an AC generator
In question 13.1 students were asked to identify the type of generator that was depicted
and to provide a reason for this classification. Question 13 is shown below in figure 4.8:
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Figure 4.8: An examination question on a generator
Source: DOE – November 2008 NSC grade 12 Physical Sciences (P1)
This question required a genetic explanation as students needed to identify what type of
generator was depicted on the basis of what components it consisted of. Most of the
students holding misconceptions regarding the AC generator offered genetic
explanations (87%). By constructing genetic explanations, students focussed on what
components the generator had, thereby revealing that 8% of the sample held the
misconception that an AC generator has split rings. Exam-script responses illustrating
this misconception are quoted below:
AC generator, because of the presence of the split rings.
AC generator because it uses split rings.
Alternating current (AC); it has two split rings and moves anti-clockwise.
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Clearly these students are confused regarding the difference in the working of slip rings,
which enables an AC current to flow in a generator, and a split-ring commutator which
enables a DC current to flow in a generator and which is also used in a motor. Olivier
(n.d., p.200, 202) explains that “ the alternating current generator has two slip-rings” and
“For a direct current generator (dynamo) which generates direct current instead of
alternating current, we can replace the slip-rings with a split-ring commutator (as used
by the dc electric motor).”
4.5.2.5 Fifth common misconception: the voltage increases when appliances
are added to a multi-plug
In question 14.3 students were asked to apply Physics principles to explain why a cut-
off switch is important in a multi-plug that has many appliances connected to it. In
answering this question, students needed to explain that as more appliances (resistors)
are connected in parallel, the total resistance in the circuit decreases, the current
increases and the components get hot unless the cut-off switch acts as a circuit
breaker. The question required a rational explanation, but a significant number of
students offered functional and genetic explanations instead. Overall students’
responses to this question yielded 16% of all identified misconceptions. Question 14.3 is
shown in figure 4.9:
Figure 4.9: An examination question on a cut-off switch
Source: DOE – November 2008 NSC grade 12 Physical Sciences (P1)
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There were 324 cases of misconceptions in the functional explanations offered by
students and this represented 69% of all misconceptions for this question. The students
who constructed these functional explanations revealed a variety of misconceptions
regarding the function and operation of a cut-off switch. A common misconception in
this type of explanation was that a cut-off switch lowers the voltage, which starts to
increase as more appliances are connected to the multi-plug. Six percent of the
students in the sample held this misconception. The idea that the voltage increases as
resistors are added in parallel is incorrect because it is the current which surges and not
the voltage. This misconception is illustrated in the following exam-script responses:
The cut-off switch reduced the build up of energy transferred to appliances to reduce heat so that
appliances can receive required energy and they cannot burn easily. The cut-off switch reduces
the high voltage in the electric equipment to reduce damage of appliances.
When you are using a multi-plug you are stepping down the voltage and saving electricity at the
same time.
It is important to have a cut off switch because-the voltage inside the plugs could build up
immensely if not used – the heat inside the wire and therefore valuable energy is lost.
Students also constructed other misconceptions regarding the multi-plug which are
discussed later in this chapter, this was probably due to the fact that many students are
not well acquainted with a cut-off switch and how it works in relation to the multi-plug.
Student interviewee nine clarified this by saying: “I didn’t have an idea what a cut-off
switch is.” This same student also illustrated the difficulty that many students have with
using scientific language consistently:
Student 9: Well, too many plugs using too much energy, electricity…maybe if you use
different machines or things that use a lot of power, and so it has happened
before in our house that the plug just wanted to blow up, because it was too much
friction or .. I don’t know? Power.
Researcher: What do you mean by power?
Student 9: Electricity.
Researcher: Electricity. What do you mean by electricity?
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Student 9: The flow of electrons.
Clearly this student is confused about the meanings of the concepts, energy, power,
electricity and current, hence the inconsistent use of these concepts. Research has
found that students use the terms energy, current, power, electricity, charge, electrical
potential, potential difference, emf and voltage synonymously (Bull et al., 2010; Cheng
& Shipstone, 2003; Periago & Bohigas, 2005; Shipstone in Driver et al., 1985). Moore
and Harrison (2004) argue that this is largely due to a lack of understanding of abstract
concepts.
4.6 OTHER MISCONCEPTIONS
Other than the five common misconceptions that occurred most frequently in the
student responses, this study revealed additional misconceptions. These other
misconceptions are discussed in this section.
4.6.1 Forces acting on two separate interacting bodies can be added, and may
add up to zero causing the bodies to remain stationary
The misconception that forces acting on two separate bodies can be added, and may
add up to zero, causing the bodies to remain stationary, was exposed in the following
interview response:
Researcher: You also wrote that the fact that the stationary car moved also indicates a greater
force by the heavier car, do you think that it is always like that, that the object that
moves is experiencing a bigger force?
Student 1: Yes, cause, I think so, because if like the um the force was the same then it
wouldn’t have moved at all like if you try and push a wall your force is not big
enough so it is not going to move at all.
In the above response to question 5.3 of the Physics exam, the student constructs a
rational explanation by applying Newton’s first law. Although the student does not
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directly refer to Newton’s first law, the student reasons that the lighter car started
moving because it was pushed harder, in other words was acted upon by a resultant
force. The student is correct in arguing that the lighter car started moving as a result of
a resultant force. However, the resultant force acting on the lighter car is not the sum of
the two forces that the two cars exert on one another, but rather the sum of all the
forces acting on the lighter car. According to Olivier (n.d., b) Newton third law force pairs
act on two different objects and can therefore not cancel each other out. The
misconception that forces of interaction acting on two objects can be added together is
a common misconception previously reported on by Halloun (1998). The above
response is also incorrect in asserting that objects do not move when exerting equal
forces on one another. Interacting objects always exert equal opposite forces on one
another and in many cases the objects may accelerate. The acceleration of an object is
not determined by the force that it exerts on another object, but rather by the forces that
are acting on it.
4.6.2 Light objects have less momentum and experience a greater change in
momentum during a collision
The misconception that light objects have less momentum and experience a greater
change in momentum during a collision was exposed in the following pre-interview test
response and interview response by student interviewee three:
The light object has little momentum and when it collides with a heavy object momentum is
transferred between them. The light object with the large momentum will now move at a higher
velocity, so the impulse of such a collision will be also more on a lighter object.
Because the impulse is like the change in, the change in momentum, from like before, and a light
car will have low momentum before it crashes and then when it does crash the, the, like energy
which is transferred between the two vehicles will increase its momentum and it will like, the
shock will be large, like the people on the inside will feel like a big force backward and their necks
will hurt or break or whatever, so the impulse, the change in momentum will like be larger.
In the above responses to question 5.3 the student constructed mechanical
explanations which focus on the momentum of the lighter car. In focussing on the
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momentum, the student exposed misconceptions regarding momentum. Lighter objects
do not always have less momentum, because momentum depends on both mass and
velocity. In this case the lighter car would have zero momentum before the collision
because it was stationary. The student continued by arguing that momentum is then
transferred and the lighter car experiences a greater change in momentum. It is
incorrect to deduce that the lighter car experiences a greater change in momentum,
because according to Newton’s third law the impulse experienced by both cars is equal
but opposite in direction (Heyns, 1999).
4.6.3 Momentum is lost or converted into heat or some other form of energy and
kinetic energy and momentum is the same property of motion
The misconception that momentum is lost or converted into heat or some other form of
energy is illustrated by the following student interviewee response:
Researcher: And you wrote: "Momentum won’t be conserved as the car’s shape will be
permanently changed", explain why you think the momentum isn’t conserved
when that happened?
Student 5: ..Umm, because if it was conserved then the momentum after the collision will
still be equal to the momentum before the collision, and obviously because there
is change in form and heat and whatever, then obviously momentum was lost.
In the above response to question 5.2 the student constructed a genetic explanation by
focussing on what happens instead of providing scientific evidence. By focussing on
what happens, the student reveals the misconception that momentum is lost or
converted into other forms of energy. Clearly, this student is confused between kinetic
energy and momentum and is using the terms as if they have the same meaning, thus
exposing another misconception that kinetic energy and momentum is the same thing.
Previous studies have also reported on the occurrence of the misconception that kinetic
energy and momentum is the same thing (Bryce & MacMillan, 2009; Lin, 1983). These
two quantities of mass in motion appear to be similar because they both incorporate
both mass and velocity.
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4.6.4 Misconceptions concerning the internal voltage of a battery
Two misconceptions about the internal voltage of a battery became evident in this
study. Firstly, students hold the misconception that a voltmeter measures the internal
voltage of the battery when it is connected across the battery in a closed circuit.
Secondly, students hold the misconception that the internal voltage of a battery is not
affected by changes in the external circuit. These misconceptions are illustrated by the
following exam-script responses to question 12.3:
The reading on the voltmeter will remain the same because the voltmeter is attached across the
battery and not the resistor. It will not be affected because the battery does not change.
Voltmeter will remain unchanged because it only measures the potential difference across the
cell.
It will remain the same because it is connected across the internal resistance and the internal
resistance stays the same.
The first two quotations above represent genetic explanations because the students
focus on what is happening. They argue that the voltmeter reading remains the same
because it is measuring the potential difference across the battery which remains the
same, thereby incorrectly implying that the voltmeter is measuring the internal voltage
which remains the same. The last quotation above represents a mechanical explanation
as the student focuses on the resistance of the battery. The student argues that since
the internal resistance of the battery stays the same, the voltmeter reading stays the
same. The student supplies no rationale as to why the constant internal resistance
leads to a constant potential difference across the battery. It seems that this student
holds the same misconception that the voltmeter is reading the internal voltage of the
battery and that the internal voltage remains unchanged by the external changes. This
misconception is incorrect because a voltmeter connected across a battery in a closed
circuit measures the terminal potential difference which is the potential difference of the
external circuit (Heyns, 1999). In addition, the internal voltage of the battery is not
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constant; it varies as the current strength varies and also as the internal resistance
varies due to slight changes in the temperature of the battery. This misconception that
the internal voltage of the battery remains unaffected by changes in the external circuit,
illustrates how students forget that they are dealing with a connected circuit (Cheng &
Shipstone, 2003).
4.6.5 The potential difference across resistors connected in parallel remains
constant when one of the resistors is removed
The misconception that the potential difference remains constant when one of the
resistors connected in parallel is removed is illustrated by the following exam-script
responses:
The reading will not change. In a parallel circuit, the voltmeter reading stays the same for all
resistors. Therefore removing one (resistor) will not change it.
It will remain the same because it is connected in parallel and parallel circuits are current dividers
and not potential dividers.
In the above responses to question 12.3, students constructed rational explanations by
applying the scientific principle that when resistors are connected in parallel the
potential difference across the parallel combination is equal to that across each of the
individual resistors (Heyns, 1999). While the principle is correct, students appear to
have overextended the principle by arguing that the potential difference across the
parallel resistors remains the same even when one of the resistors burn out.
4.6.6 DC motors and generators have slip rings and motors and generators are
the same type of machine
The misconceptions that dc motors and generators have slip rings and that motors and
generators are the same type of machine, are illustrated by the following exam-script
responses to question 13.1:
A DC generator. There are slip rings used.
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DC motor, there is a direct current flowing to the coil and there are two slip ring indicating that this
is a DC motor.
Motor generator because of it uses motors to generate it fields and it is accumulated a lot and in
magnetism.
It is the motor generator because it has the x and y.
Students may be confused about the differences between motors and generators due to
their similar structure and components. It is important for teachers to emphasise that
“motors use electrical energy to produce mechanical energy” and that “generators use
mechanical energy to produce electrical energy” (Olivier, n.d., a, p.200).
The following excerpt from an interview also illustrates the confusion between slip rings
and a split ring and between motors and generators:
Researcher: In your worksheet you wrote that: “this generator is a dc generator, because of its
slip rings.” Tell me more about the difference between an ac and a dc generator.
Student 4: Ok, I don’t know. Um, ac, am I right, ac generators, ………….…, dc generators
use electricity to create mechanical energy, I think, and ac generators, …, yah,
use mechanical energy to create energy, I think, I am not sure, cough, so what I
think mam, is that because an ac generator is slip ring and a dc one is, no a dc
one is slip rings and an ac one is split rings, that’s what I mean.
Researcher: Would you say these in the diagram are spilt rings or slip rings?
Student 4: Slip.
Researcher: Have you done an experiment in the class, where you have built one or have you
seen an ac or dc generator?
Student 4: Experiment no; it’s what I saw from the textbook.
The above excerpt also illustrates the fact that students often do not get to do the
practical linked directly to the work. In the teacher interviews, teacher two confirmed that
although “the kids are visually stimulated”, and practicals can “have a HUGE impact”,
“due to the big class ... and expensive equipment, you can’t always let everybody do his
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own experiment” and “if you had enough time…and enough resources” it would be
easier to do practicals. Even so, Ausubel (in Novak, 2004, p.32) maintains that
“students require concrete-empirical props to develop abstract concepts.”
4.6.7 A cut- off switch works just like a normal switch, it can be switched off to
save electricity
The misconception that a cut- off switch works just like a normal switch is illustrated by
the following exam-script responses:
We need switch so we can switch on and off any time we need to switch.
It is important because you can switch off the unused plugs in order to save electricity.
A cut-off switch is also important to save energy as additional energy which is not required will not
be use.
The above responses are all functional explanations that focus on the function of a cut-
off switch thereby exposing the misconception that a cut-off switch works like a normal
switch. These responses are incorrect because a cut-off switch is not like any other
switch that you can switch on or off. A cut-off switch is a trip-switch that automatically
breaks the circuit when the current is dangerously high.
4.6.8 Household appliances such as those connected to a multi-plug are
connected in series
The misconception that household appliances such as those connected to a multi-plug
are connected in series is illustrated by the following exchange that took place during a
student interview:
Researcher: What makes the current high?
Student 7: If you use too many appliances like them all in one socket.
Researcher: Why should that cause the current to increase?
Student 7: It needs to be more places at once.
Researcher: What do you mean by this?
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Student 7: There is now a lot of them together
Researcher: Are the appliances connected in series or parallel?
Student 7: Probably series
Researcher: Why do you say so?
Student 7: Because if one appliance breaks the other will still keep going.
In the exchange above, the student focuses on the physical connection of the multi-
plug, thereby presenting a mechanical explanation which reveals the misconception that
household appliances are connected in series. Although the student correctly relates
that the current will increase as more appliances are connected to the multi-plug, the
foundation to this assertion is flawed as the student believes this increase to be due to a
series connection of appliances. Seven of the students interviewed believed that the
appliances were connected in series. Pilatou and Stavridou (2004) found in their
research with primary school children that even though they handle many household
electric appliances every day they do not know that the electric installation in a house is
a parallel connection. They argued that it is because students “cannot observe the route
they follow behind the sockets” (Pilatou & Stavridou, 2004, p.698).
4.7 INTERPRETATION OF THE RESULTS REGARDING POSSIBLE SOURCES
OF MISCONCEPTIONS
In this section I will interpret what student explanations revealed about possible sources
of student misconceptions. I will discuss the individual, social interactions, language,
assessment and context as possible sources of misconceptions, as well as the
relationship between these factors.
4.7.1 The individual as a source of misconceptions
Observation, experience and understanding are influenced by an individual’s prior
beliefs and knowledge (Carr et al., 1994; Strike, 1983). In everyday life students
observe what happens in various situations and then construct explanations in terms of
their own beliefs and misconceptions, hence their inclination to offer genetic
explanations. The tendency to describe what is happening instead of why it is
happening was most prevalent in this study. In total, 41% of the misconceptions found
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in this study were found in genetic explanations. An example of such a misconception is
illustrated by the following response: “The cut-off switch disables the flow of electricity
when not in use" to the question: “Using principles in Physics, explain clearly why this
cut-off switch is important.”
Students are also accustomed to observing the physical features of objects, hence their
inclination to offer mechanical explanations of phenomena by only providing evidence in
terms of an object’s physical features. Mechanical misconceptions were also highly
prevalent in this study (37%), indicating that students are not in the habit of supplying
laws of Physical Sciences as evidence for phenomena and rely on the type of
mechanical reasoning that is used in everyday life. This is especially the case when
students are asked to explain a phenomenon set in an everyday context. Hence, the
construction of misconceptions such as “heavier cars exert more impact on lighter cars
during a collision” as illustrated by this response: “A lighter car will easily get crushed
due to the mass of the heavier. The heavier the mass, the greater the force.” It is clear
from the examples of mechanical explanations provided in this study that students tend
to focus on the observable physical properties of objects. When students do this they
may expose misconceptions about the physical properties of objects and the effect
these properties have on certain situations.
4.7.2 Social interactions as a source of misconceptions
Although students construct their own explanations and conceptions in order to make
sense of their experiences and observations, these constructions are socially
negotiated. According to the theory of social constructivism, knowledge is attained,
developed and validated through social interactions (Kibuka-Sebitosi, 2007; Matthews,
1998). Hence, a second source of misconceptions is the interaction between students
and various social role-players such as teachers.
In this study I found that teachers and textbook writers in trying to simplify matters
construct explanations which may be misinterpreted by students. For example, students
are taught that total linear momentum is conserved during collisions and explosions in
closed systems. This statement may cause students to construct the misconception that
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momentum is not conserved in open systems, and that it is somehow converted to
something else or lost, like energy. The following student response, by student
interviewee five illustrates this misconception:
If it was conserved then the momentum after the collision will still be equal to the momentum
before the collision, and obviously because there is change in form and heat and whatever, then
obviously momentum was lost.
The above response is a genetic explanation which focuses on what happens, thereby
exposing a misconception about what happens in an open system. In order to prevent
this misconception, teachers need to explain that when objects collide or explode the
momentum that is transferred from one object to another does not only result in the
displacement of that object as a whole, but that it also increases the momentum of the
particles in the object which can then move within that object. For example, when a car
crumples up upon impact, some of the momentum that is transferred is used for linear
translational motion and some increases the momentum of the car’s particles. The
increase in internal momentum of the car’s particles results in the car changing shape. It
is also important for teachers to emphasise that not only is momentum also transferred
and used for internal motion of the particles within an object, but that momentum is also
transferred between the colliding bodies and the surface, air and objects inside of the
colliding bodies. Working with closed systems limits the number of objects that are
involved in the transferral of momentum, but total momentum still remains constant in
an open system. Explaining the conditions set by Physical Sciences is vital as it enables
students to understand how Physical Sciences are applied to the real world (Bryce &
MacMillan, 2009).
Teachers may also cause student misconceptions by using anthropomorphic
explanations to simplify abstract theories. For example, teachers may attempt to
illustrate the concept of electrical current by explaining that electrons choose the path of
least resistance. Although Treagust and Harrison (2000, p.1165) argue that
anthropomorphisms are “acceptable elements of effective pedagogical content
explanations” and that they enable students to relate to abstract concepts,
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anthropomorphisms may cause students to believe that inanimate particles really do
have human attributes. Few of the student responses analysed in this study could be
classified as anthropomorphic explanations, nevertheless, the following exam-script
response illustrates how students may construct anthropomorphic misconceptions: "So
that electrons would get time to rest, when switch it on they perform a good work."
Teachers may also cause misconceptions by teaching the relationship between
variables and the calculation of variables without spending enough time on developing
students’ conceptual understanding of the variables found in scientific laws. This may
lead to the misconception that the various variables in a scientific relationship are all the
same thing. This is illustrated by the following response by student interviewee nine:
Well, too many plugs using too much energy, electricity…maybe if you use different..machines or
things that use a lot of power, and so it has happened before in our house that the plug just
wanted to blow up, because it was too much friction or .. I don’t know? Power.
The following response by the first teacher that was interviewed also illustrates how
important it is to develop conceptual understanding of the basic concepts in order to
prevent misconceptions:
I would say improper preparation before hand. That you just fire away. That you teach them
something for which you did not really prepare the basic concepts enough. In Science very often
they come and they have no basic concepts and you fire away like with electricity and they have
no idea really.
Teachers are not the only social role-players who may cause misconceptions, society in
general and social language also affects the construction of misconceptions. This effect
is discussed in greater detail in the next section.
4.7.3 Language as a source of misconceptions
The construction of knowledge is influenced by language. How students interpret new
information and link it to their preconceptions is influenced by how well they understand
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the language used by their teachers, peers or textbooks. Students’ understanding is
also influenced and reinforced by their own ability to articulate their understanding
(Sawyer, as cited by Berland & Reiser, 2008). Hence, students with a poor command of
language construct misconceptions as a result of not being able to understand the
learning material. In this study I classified many student responses as inconclusive in
terms of misconceptions because the language used was so poor that it was not clear
whether the student held a misconception or not. Many of the students who wrote this
exam were writing it in their second language, which explains why their command of
English is so poor. The following exam-script response, to a question that required
principles of Physics as evidence, illustrates the problem that many students have with
the use of language: “Because the traffic officer always he/she see the accident of many
cars.” The teachers that I interviewed also explained that: “I still think that there is a
language thing involved because they, they just do not sometimes understand what you
are explaining to them” and “the reading level that is a big problem with some of our
students.”
Students’ grasp of social language is not the only dimension of the effect that poor
language has on the formation of misconceptions. Lemke, cited by Scott et al. (2007,
p.46), explains that “learning science involves learning to talk science.” Students who do
not understand scientific language will struggle to understand Physical Sciences and
may construct misconceptions based on their misunderstanding of scientific
terminology. Misconceptions revealed in this study, such as “energy, voltage, electricity,
current, and power are the same thing” originate because students do not understand
scientific language. The incongruence between scientific language and everyday
language is another source of misconceptions. Often words do not have the same
meaning in scientific language as what they do in everyday language and this causes
misconceptions. Examples of such misconceptions revealed in this study are: mass is
the same as weight and energy is lost. In everyday language weight is regularly used as
a synonym for mass and social media often advertises weight loss products. Physical
Sciences, however, clearly differentiates between mass and weight. In everyday
language it is also acceptable to speak of lost energy; modern society continually
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emphasises the need to save energy as if we are destroying it. Scientists, however,
explain that energy cannot be destroyed and that the problem actually is that we are
transporting, transforming and degrading energy into forms that we are as yet unable to
exploit. The incongruence of everyday language and scientific language as a source of
misconceptions is illustrated by the following student interview response, by student
three:
They try to tell us that it is not lost, it is just converted and so forth, but for me to use, like,
layman’s terms and to explain the science behind it, to understand it better, I try to explain it in
things that are easy to understand, like lost and not converted.
Scientific language not only differs from social language in terms of the meaning of
certain terms, it also includes a host of symbols that are not used in social language and
that must be mastered by students. In the next section, on assessment as a possible
cause of misconceptions, I will discuss how an over-emphasis of the manipulation of
these symbols causes misconceptions about their meaning.
4.7.4 Assessment as a source of misconceptions
Assessment, in the subject-field of Physics, places a significant emphasis on exemplar-
type calculation questions. The 2008 NSC Physics exam paper consists of 21%
explanation-type questions and 79% non-explanation-type questions. In order to meet
performance expectations teachers teach to the test by training students to answer
calculation-type questions. This training leaves teachers with almost no time for
engaging in deeper conceptual development and thus assessment becomes an indirect
source of misconceptions. The following response by student interviewee ten illustrates
the emphasis on exemplar-type calculation questions:
You know going through papers it’s more like these days you just get the same questions and
then, you like, kind of like store it in your head, we don’t really sometimes understand what’s
happening and what… what’s going on we just store it.
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In addition, exemplar-type calculation questions often assess scientific knowledge in a
fragmented decontextualised manner. In other words, each scientific principle or law is
assessed separately, thereby creating the impression that each law applies only to
certain situations. Also, the situations sketched in assessment questions seem artificial
because certain contextual features are omitted. This creates the impression that
Science does not apply to real-life situations. The effect that context has on the
formation of misconceptions is discussed in greater detail in the next section.
4.7.5 Context as a source of misconceptions
In order to improve on the decontextualised nature of traditional assessment,
contemporary assessment questions require the application of knowledge to everyday-
life situations. However, because students are accustomed to making sense of their
experiences and observations in terms of their pre-knowledge, which includes
misconceptions, exam questions set in everyday-life situations prompt students to apply
their pre-knowledge and not their scientific knowledge. In the exam analysed in this
study, students were asked to apply their scientific knowledge to everyday contexts
such as a traffic officer observing the damage at an accident scene. The familiar
accident scene prompted students to use their preconceptions regarding the interaction
between two objects, thereby exposing the misconception that heavier objects exert a
greater force on lighter objects, than what lighter objects exert on heavier objects. This
misconception is illustrated by the following student response: “The statement by the
traffic officer is correct because the passenger in a heavier car has weight and the
material of the car has a higher mass and its velocity is also high which means the car
is very strong, as for the lighter car it is not strong.”
Question 14.3 of the Physics exam was also set in an everyday-life context. The context
in this question was the overloading of a multi-plug. Many students seemed to be
familiar with the overloading of a multi-plug and were prompted to use their
preconceptions about how a multi-plug functions. This exposed the misconception that
the overloading of a multi-plug is dangerous because it causes the voltage to increase.
The structure of the multi-plug and the function of the cut-off switch, however, seemed
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to be unfamiliar to many students. Student interviewee nine explained that “I didn’t have
an idea what a cut-off switch is.” Students needed to be aware that the structure of the
multi-plug is such that the appliances are connected in parallel to a multi-plug. This was
necessary so that they could deduce that the current would increase as more
appliances were connected to the multi-plug. During the student interviews conducted in
this study, it became evident that students are not familiar with the connection of
household appliances and that they hold the misconception that household appliances,
such as those connected to a multi-plug, are connected in series. Many students that
were unfamiliar with the cut-off switch likened it to a normal switch that can be switched
on or off. They then proceeded to construct the misconception that a cut-off switch can
be switched on or off in order to save electricity. This illustrates how students may
construct a misconception by connecting an unfamiliar context with a familiar one. It
seems that although it is important for students to be able to apply their knowledge, the
use of everyday contexts may be confusing, especially when students are not familiar
with the everyday context used in examinations. During an interview teacher one
commented that students “just sometimes do not understand what you are explaining to
them, because it’s not in their world, we take it that they all have experience and that
they all read and that they all have general knowledge, and these days they have very
little general knowledge.” When students have not used, explored or learned about
physical objects such as a cut-off switch, then these objects and the manner in which
they function do not form part of students’ conceptual frameworks even if these objects
can be found in their homes.
Students also construct misconceptions by applying ideas, which are valid in some
contexts, to contexts where they are invalid. In question 12.3, of the Physics
examination which forms part of this study, a resistor connected in parallel burns out
and students are required to predict the effect of this change on the voltmeter reading.
Some students responded by arguing that the voltmeter reading would change as a
result of an increase in the total current running through the circuit caused by the
resistor burning out. Although it is true that for resistors in series the removal of one
resistor leads to a decrease in resistance and an increase in current, when resistors are
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connected in parallel the removal of a resistor leads to an increase in the resistance and
a decrease in the current.
Students may also create a separate context of application for scientific knowledge
when it does not match their ideas. As a result, misconceptions and scientific
knowledge co-exist within students’ conceptual frameworks, each within their own
separate context (Klassen, 2006; Tytler, 1998). This was evident in students’ responses
to question 5.3. Although the context in question 5.3, the accident scene, is a familiar
everyday-life context which prompts students’ preconceptions, it is also a context often
used in Physics textbooks. Therefore, some students realised that the question
demanded the application of scientific principles such as Newton’s third law. However,
since some of these students also held misconceptions contradicting Newton’s third
law, they constructed a separate context of application for Newton’s third law. This is
illustrated in the following response by student interviewee one:
... because if like the um the force was the same then it wouldn’t have moved at all like if you try
and push a wall your force is not big enough so it is not going to move at all.
The above response illustrates how a student can confine the context of application of
Newton’s third law to situations where the objects do not move. Students who believe
that heavier objects exert a greater force, may alternatively confine the context of
application for Newton’s third law to the interaction between objects of equal mass and
strength. In the responses to question 5.3 some students even applied both Newton’s
third law and their contradicting misconceptions in one explanation, as illustrated below:
Using Newton's third law the car with a heavier mass will exert a greater force on the car with a
lighter mass.
This response illustrates how scientific principles can be loosely assimilated within the
conceptual framework of students, without proper conceptual understanding.
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In this section I reported that everyday-life contextual questions prompt students to
apply their misconceptions instead of scientific knowledge. I also discussed how
students create separate contexts of application for their misconceptions and scientific
knowledge, thereby allowing both to co-exist within their contextual frameworks and
creating misconceptions about the range of application of scientific knowledge. The
discussion in this section also illustrated how misconceptions are constructed when
students over-extend the range of application of scientific knowledge to a context where
it is not valid.
4.7.6 Graphical representation of the possible sources of misconceptions and
their link with misconceptions
In order to clarify the possible sources of misconceptions I constructed the following
concept map as shown in figure 4.10:
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Misconceptions
Hidden or
Figure 4.10: A concept map illustrating the relationship between
misconceptions and the causes of misconceptions
Source: Compiled by researcher
Exposed:
Complex
or
Incomplete
or
Simple
Non-
response
8, 6%
Responses
with poor
language
Individual
person
Everyday
Language
Vs
Scientific
Language
Assessment emphasises calculation-
type questions and fragments
knowledge
Society:
Teachers
Family
Peers Everyday Context
Vs Science
Exemplar Context
Interaction Co
nstru
cts
Co-construct
Ca
use
s
Causes
Use
bo
th in
co
nsis
ten
tly
Influences Influences
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The concept map indicates the various causes of misconceptions. These causes
include both individuals and society who co-construct misconceptions. Misconceptions
are also caused because individuals together with society use scientific language and
everyday language interchangeably, despite there often being differences between
them which may lead to misconceptions. Society also influences assessement trends
which in turn influences teaching strategies and may cause student misconceptions.
The introduction of everyday contextual questions into assessment also influences
student misconceptions as the context cues the use of preconceptions held by students.
Exemplar-type questions often ignore certain everyday-life conditions which creates the
misconception that Science does not apply to the real world.
In the concept map I also classified misconceptions as either exposed or hidden. I
presented the relationship between exposed misconceptions by placing them in a
hierarchy. I placed complex rational constructs at the top of the hierarchy, because
students that had constructed rational misconceptions had applied scientific concepts
and theories in these constructions, albeit incorrectly. The main cause of these complex
misconceptions is the poor understanding of the relationships between variables in the
basic laws of Physical Sciences.
I classified the misconceptions found in mechanical, genetic, functional, teleological and
practical explanations as “incomplete constructs” and placed them below complex
rational misconceptions in the hierarchy of misconceptions. I placed them lower in the
hierarchy because students referred only to physical properties, functions and
phenomena in a fragmented manner instead of referring to scientific theories as
evidence in their explanations. I classified them as incomplete because during student
interviews I found that students who initially gave mechanical explanations provided
rational explanations upon probing. This shows that students do not realise what
explanation-type questions expect from them, don’t always have enough time to
construct rational explanations and do not have experience in constructing rational
explanations.
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I classified misconceptions found in analogical, anthropomorphic and metaphysical
explanations as “simple constructs” and placed them below the incomplete constructs in
the hierarchy of misconceptions. I did this because students who create simple
constructs explain occurrences by relating them to other things from their everyday
experiences, rather than by applying scientific concepts to explain the occurrence.
Lastly, I classified the misconceptions found in tautological explanations, those
explanations classified as inconclusive in terms of the types of explanations, and the “no
responses” as hidden misconceptions. I did this because students who responded in
these ways did not reveal whether or not they held any misconceptions.
4.8 CONCLUSION
In this chapter, data regarding the performance of students in explanation-type
questions and the frequency of misconceptions revealed in various explanation-types
was presented. Data illustrating these misconception-types as well as specific student
misconceptions were also discussed. The chapter ended with an interpretation of what
misconception-types reveal in terms of possible sources of misconceptions. In the final
chapter the findings are summarised and possible recommendations are made on
addressing misconceptions and the performance of students in explanation-type
questions.
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CHAPTER 5
SUMMARY, RECOMMENDATIONS AND CONCLUSIONS
5.1. INTRODUCTION
This study analysed the explanations of students found in their responses to questions
in the 2008 NSC Physics examination. Previous studies I have already referred to have
investigated student misconceptions on specific topics in Physical Sciences through
student interviews. In this study I have reported on a large scale project which involved
the analysis of 921 examination scripts, focussing on student explanations to questions
on a range of Physics topics. I sought to understand the nature of the misconceptions
evident in these explanations by firstly identifying characteristics of the explanations. In
my analysis I used a framework developed by Dagher and Cossman that they employed
for verbal explanations in a Physical Sciences class. I found this framework to be
effective as it enabled me not only to identify specific misconceptions but also to classify
these misconceptions based on characteristics of the explanation offered. I believe that
this method of analysis does offer researchers a reliable and efficient way by which
written student explanations can be probed for misconceptions.
Nevertheless, delving into written student’ explanations for misconceptions remains a
complex task. Students often construct brief off the cuff responses or poorly articulated
responses, hardly giving one a glimpse of their understanding. This is especially the
case during formal assessments where students have a limited time to express
themselves. It is therefore important to further investigate the characteristics of
misconceptions exposed through written explanations. I have done this by conducting
both student and teacher interviews. The content analysis of student’ explanations
documented in both written exam scripts and interview transcripts has enabled me to
find answers to the following research questions which I formulated at the beginning of
this study:
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(1) What are the common student misconceptions that are revealed in a high
stakes Physics examination?
(2) How do students perform in explanation-type questions?
(3) What do explanation-types reveal about student misconceptions?
This chapter reports on the key findings of the study, discusses the implications for
teachers and other role-players in education, critiques the study, and also makes
recommendations for future studies.
5.2. SUMMARY OF MAJOR FINDINGS
In this section the main findings that were constructed through the analysis of the data
will be reviewed.
5.2.1 Common misconceptions in Physics
Through an analysis of the content of student’ explanations and the types of
explanations offered by students, I discovered specific misconceptions held by students.
The following misconceptions regarding mechanics were exposed:
• heavier/stronger cars exert more impact on lighter/weaker cars during a collision;
• mass, weight, force, power, and strength is the same thing;
• weight and force are properties of an object, just like mass;
• forces acting on two separate interacting bodies can be added, and may add up
to zero, causing the bodies to remain stationary;
• Newton’s third law only applies to closed systems;
• light objects have less momentum;
• light objects experience a greater change in momentum during a collision;
• momentum is lost or converted into heat or some other form of energy;
• kinetic energy and momentum is the same thing;
• energy is lost.
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I also discovered the following student’ misconceptions regarding electricity:
• total external resistance decreases when an external resistor connected in
parallel is removed;
• changes in the external circuit have no effect on the internal voltage of the
battery;
• a voltmeter connected across a battery in a closed circuit measures the internal
voltage of the battery or the emf of the battery;
• the potential difference across resistors connected in parallel remains constant
when one of the resistors is removed, because parallel resistors are not voltage
dividers;
• a split-ring is found in an AC generator;
• slip rings are found in DC motors and generators;
• generators are the same as motors;
• the voltage increases when appliances are added to a multi-plug;
• energy, voltage, electricity, current, and power is the same thing;
• a cut-off switch saves electricity by cutting off the flow of electricity to appliances
which are off but are still drawing small currents;
• a cut-off switch works just like a normal switch, it can be switched off to save
electricity or to prevent a fire;
• household appliances such as those connected to a multi-plug are connected in
series.
5.2.2 Student performance in explanation-type questions
The sample of 921 students achieved an average of 17, 4% percent for the explanation-
type questions. They performed 8,4% better in the non-explanation-type questions.
These findings are in line with previous studies that have shown that students perform
“particularly badly in questions which require them to give qualitative responses” (Bryce
& MacMillan, 2009, p.740). Also, despite the fact that misconceptions are not always
exposed by student explanations, a significant number (27,4%) of student explanations
did expose misconceptions.
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The poor performance of students in explanation-type questions may be attributed to
the fact that explanation-type questions are more likely to expose the misunderstanding
of students. Students are trained to rote-learn calculation-type questions in preparation
for examinations, thereby enabling them to provide the correct answer for such
questions without exposing their misconceptions. Rote learning of calculation-type
questions is advanced by examiners who emphasise non-explanation-type questions.
Non-explanation-type questions constituted 79% of the 2008 NSC Physics examination.
Since calculation-type questions are emphasised in high stake examinations, teachers
spend many hours training their students to answer these types of questions. This
leaves teachers very little time to develop the conceptual understanding of their
students.
It is also important to remember that although this study focused on explanation-type
questions, misconceptions affect student performance in other question-types as well.
The sample of students investigated in this study achieved an overall average of 24%
for the 2008 NSC Physics examination which is comparable to the average of less than
30% achieved by 45% of the entire group of students who wrote the Physical Sciences
examination.
5.2.3 What explanation-types reveal about misconceptions
The types of explanations constructed by students holding misconceptions reveal
information about both the nature of misconceptions as well as the source of the
misconception. This is discussed next.
5.2.3.1 Explanation-types reveal the nature of misconceptions
The most prevalent cases of misconceptions were found in genetic (41%) and
mechanical (37%) explanations. It became clear from the analysis of the explanations in
the examinations scripts and the interviews that students have a naïve, superficial and
fragmentary understanding of scientific phenomena that is based upon their
misconceptions. These misconceptions are not theoretically grounded, as students use
the contextual features of the problem situation as evidence for their misconceptions.
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This finding correlates well with other studies that allude to the context dependency of
students’ reasoning, found amongst students entering higher-level education (Hammer,
2000; Hamza & Wickman, 2008; Knight, 2002). When assessment questions test the
ability of students to apply knowledge to everyday scenarios, a particular problem
context activates a particular alternative conception (Clough & Driver, 1986; Driver et
al., 1985; Palmer, 2001), steeped in everyday language (Tytler, 1998). This was also
evident to a large extent in the common misconceptions that were identified in this
study. For example, in question 5.3 where students needed to explain why the
passengers in a heavier car were less likely to get injured during a collision; the majority
of students either referred to the physical property of the cars or described what was
happening, thereby activating the misconception that heavier cars exert a greater force.
Thus I found that the main types of misconceptions held by the students in the sample
were misconceptions related to what happens to physical objects during certain events
(genetic misconceptions), and misconceptions related to how certain physical properties
affect what happens to objects or bodies (mechanical misconceptions). Since students
use their misconceptions to construct explanations about their everyday experiences
and observations, it is understandable that students tend to construct mostly genetic
and mechanical explanations. These explanation-types may then reveal misconceptions
about what happens in certain situations and about how observable physical properties
affect certain situations.
To a lesser degree students held misconceptions found in functional (12%) and rational
(5%) explanations. In the erroneous functional explanations students revealed
misconceptions regarding the function of objects, and referred to the function of an
object rather than offering a rational explanation based on Physics principles. In
question 14.3, for example, some students held the misconception that a cut-off switch
is important because it lowers the voltage and saves electricity. In the erroneous
rational explanations that students constructed, students revealed misconceptions
regarding the relationship between various physical quantities. Although students
constructing these types of explanations attempted to apply laws of Physics to explain
the phenomena, they did so incorrectly. These students often only considered two of the
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variables in a Physics equation and neglected the third variable. For example, in
question 5.3 students argued that the heavier car has more momentum because p=mv.
5.2.3.2 Explanation-types reveal the sources of misconceptions
Students themselves are a source of misconceptions. They view the world through the
lenses of their own beliefs (Carr et al., 1994; Strike, 1983) and construct explanations
as to how the world around them works (Smith, diSessa & Roschelle, 1993), based on
these beliefs. Hence their inclination to either formulate genetic explanations (41% of
misconceptions found in this study), by describing what happens, or mechanical
explanations (37% of misconceptions found in this study) by providing evidence in terms
of an object’s physical features.
The interaction between students, their peers, their family, their teachers, their
textbooks and even scientists’ theories are another source of misconceptions. Teachers
and textbook writers, in trying to simplify matters, construct explanations which are
misinterpreted by students. For example, when students are taught that momentum is
conserved during collisions and explosions in closed systems, students may construct
the misconception that momentum is not conserved in open systems and that it is
somehow converted to something else or lost, like energy. Real world problems rarely
adhere to the conditions under which scientific theory exists; thus scientific theories and
their conditions of application can be a source of misconceptions. The classroom
environment and other motivational factors also influence the conceptual development
of a student. If a student is not motivated to learn it will affect the way that new
information is interpreted and whether or not it will be connected to existing knowledge
frameworks.
Language is another source of misconceptions. The manner in which students interpret
new information and link it to their preconceptions is influenced by how well they
understand the language used by their teachers, peers or textbooks. Many of the
students who wrote this exam were writing it in their second language, which explains
why their command of English is so poor and why they hold many misconceptions.
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Misconceptions revealed in this study, such as “energy, voltage, electricity, current, and
power is the same thing” originate because students to not understand scientific
language. The incongruence’s between scientific language and everyday language is
another source of misconceptions. Often words do not have the same meaning in
Physical Sciences as in everyday language, this causes a misconception such as that
mass is the same as weight or that energy is lost.
Assessment causes misconceptions by over-emphasising exemplar-type problems and
selected response questions, by decontextualising knowledge and by using an
unfamiliar context or even by using everyday contexts. The influence of assessment on
misconceptions extends even further, as the stress caused by assessment hinders the
development of students’ conceptual understanding. In this study I found that the 2008
NSC Physics exam consists of 21% explanation-type questions and 79% non-
explanation-type questions, thereby illustrating the over-emphasis of exemplar-type
calculation questions which encourages rote learning.
The introduction of contextual application questions has also affected the occurrence of
misconceptions, because the everyday-life situations act as contextual cues to
misconceptions. Also, the introduction of restrictions in the application of Physical
Sciences theory impacts the formation of student misconceptions. For example, when
students are told that conservation of momentum only applies in closed systems, they
develop the misconception that Physical Sciences only applies to the context sketched
in Physical Sciences examples and that momentum is not conserved in open systems.
5.3. IMPLICATIONS FOR TEACHERS AND OTHER ROLE-PLAYERS IN
EDUCATION
These findings have important implications for teaching and learning. Research shows
there is often little or no change in conceptual understanding before and after formal
instruction and that students are unable to apply the concepts that they have studied to
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certain tasks (Walsh, Howard & Bowe, 2007). A possible scenario which contributes to
this status is that at school there is a strong focus on the solving of problems by the
direct application of previously learnt algorithms. Such problems often appear in
textbooks and it would be more apt to refer to these “problems” as exercises since they
provide practice to the students in applying an algorithm, and they merely serve to
reinforce what has been learned in class. Many studies have shown that although
students are able to solve these quantitative problems by simply plugging values into
formulae and obtaining a correct answer, they lack a fundamental understanding of the
concepts to solve more complex problems (e.g., Ding, Reay, Lee & Bao, 2009; Hunt &
Minstrell, 1994; Leonard, Dufrense & Mestre, 1996; Tuminaro & Redish 2005). The
predominance of this plug-and-chug approach has meant that students are given scant
opportunity to engage qualitatively with concepts in Physics. This was abundantly
evident from the analysis of student responses to the explanation-type questions in this
study where it was clear that students had little or no understanding of the Physics
concepts. Reasons for this scenario include the heavy emphasis in high stakes
examinations being placed on tasks which lend themselves to a plug-and-chug
approach. This was the case in the Physics examination which formed the focus of this
study where the majority of questions could be solved in this way. Therefore, I
recommend that examiners work towards developing a better balance between the type
of questions that target the conceptual knowledge of students and predictable
quantitative questions.
In light of this finding I recommend that a more deliberate and concerted effort be made
to engage students with their conceptual understanding of scientific phenomena.
According to Walsh, Howard and Bowe (2007), a large body of research in Physics
education has reaffirmed research from cognitive psychology that for students to
develop their conceptual understanding in Physics, instruction must first start with their
prior conceptions (e.g., Redish, 2003; Redish, Saul & Steinberg, 1998; Roth, 1990). As
pointed out earlier, these prior conceptions which often are misconceptions, are
resistant to change and traditional approaches such as those described above make
little or no difference to the conceptual beliefs of students. An effective teaching
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approach must allow for students to restructure their own understanding by first seeing
where, when and why their conceptions fail. Only after this can students start to build up
a new and correct understanding. Studies that have explored qualitative discussions in
the teaching of Physics have concluded that this is an effective means of reducing the
number of misconceptions (e.g., Eryilmaz, 2002; McConney, 1992; Nussbaum &
Novick, 1982). Such an approach would entail using conceptual questions to help
students make explicit their conceptions of a phenomenon, presenting discrepant
events to create conflict between the exposed preconception and the observed
phenomenon the student cannot explain, and making students aware of this conflict.
In addition to the use of qualitative discussions the use of writing activities is
recommended as a complimentary approach to developing conceptual understanding
and dealing with personal misconceptions (Carlsen, 2007; Hein, 1999; Mintzes et al.,
2001; Treagust et al., 2001). Emig, cited by Grimberg and Hand (2009, p.504), argues
that “because writing is often our representation of the world made visible, embodying
process and product, writing is more readily a form and source of learning than talking.”
Furthermore, as indicated in this study, many students do not have the linguistic ability
to cope with writing exams, hence the use of writing activities in a supportive
environment such as the classroom has “an added benefit for all of the students,
whether English is their first language or not: that is their communication skills are
enhanced” (Hein,1999, p.140). Teachers can use writing activities such as folder
activities (Hein, 1999) or Science Writing Heuristic (SWH) activities (Akkus et al., 2007;
Grimberg & Hand, 2009; Hand, 2004) to develop the conceptual understanding of their
students. Hein (1999) describes her folder activities as a collection of writing activities
which require students to explain a problem or a concept in their own words and with
enough detail so that someone who did not attend the class would be able to
understand their explanation. Akkus et al., (2007, p.1748) describe the SWH as a
different option to the conventional laboratory report; the SWH requires students to
complete sections on: “questioning, knowledge claims, evidence, description of data
and observations, and methods, and to reflect on changes to their own thinking.” Hence,
authors of Physical Sciences textbooks should design and include more explanation-
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type tasks such as those which formed the focus of this study so that students are
forced to engage qualitatively with Physical Sciences concepts.
Two other teaching approaches that have been highlighted in this study are the use of
concept maps and practical investigations. Teachers can use concept mapping as a
strategy to develop student conceptions by firstly guiding students through the process
of constructing a concept map and then by giving them the opportunity to construct their
own concept maps at the start of a new content area. Concept maps can be used by
teachers to identify student’ preconceptions and further inform the teaching process
(Trowbridge & Wandersee, 1998). Since concept maps are intended to represent the
“cognitive networks that have been constructed by students in the process of learning”
(Klassen, 2006, p.834) they can be modified by the students throughout the learning
process in order to allow for both reflection on, and the extension of, the student’s
understanding (Mintzes et al., 1998). In this study I found that many students held the
misconception that energy, voltage, electricity, current, and power are one and the
same thing. The use of concept mapping of these basic concepts will be particularly
useful in diagnosing this misconception and in developing the students’ conceptual
framework of these concepts. Since students use their preconceptions to construct
explanations for their experiences and observations, it is important for teachers to
provide them with new experiences such as practical experiments which are anomalous
when compared to their preconceptions. In this study I found that many students did not
know the difference between a split-ring commutator and slip rings. The use of practical
investigations will assist students in addressing such misconceptions. Research also
indicates that learning outcomes of practical investigations can be improved by
introducing techniques such as “open-ended investigations that devolve as many
decisions as possible to the students” (Moore & Harrison, 2004, p.1). Predict-Observe-
Explain (POE) is another technique where students are shown an authentic situation,
are then asked to give their prediction about how a specific change to the situation will
affect the situation, then get to observe the changes, write down their observations, and
lastly attempt to reconcile their predictions and observations (Gunstone & Mitchell,
1998). The in-service training of teachers regarding the identification of misconceptions
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and the remediation of misconceptions, through the use of alternative teaching
approaches such as those mentioned in this section, is a recommendation of this study.
Research has shown that alternative teaching approaches designed to develop
conceptual understanding, such as those discussed in the previous paragraphs, are
seldom employed due to time constraints (Ruiz-Primo, Tsai & Schneider, 2010). Over
laden syllabi do not allow adequate time for conceptual reflection (Canpolat, 2006;
Zuzovsky & Tamir, 1999). Metz (in Beeth & Hewson, 1999, p.753) argues that the
“strategic selection of a small number of domains for children’s science, together with
the scaffolding of scientific inquiry in interaction with the scaffolding of relatively deep
understanding within these spheres, more effectively can support children’s construction
and refinement of scientific knowledge.” The issue of having fewer topics in the
curriculum will need to be seriously looked at by South African curriculum planners as
we currently have a curriculum which is considered by most teachers to be overloaded
(Kriek & Basson, 2008).
5.4. CRITIQUE OF THE STUDY
This study is a content analysis, which seeks to make meaning out of students’
responses to the explanation-type questions found in the 2008 NSC Physics
examination. The strength of the study is that I collected both numerical and textual data
from a relatively large sample of 921 student examination answer booklets. The
analysis of the student examination responses was supplemented with local school-
based tests and interviews in order to improve the validity of the data. However, despite
these strengths, the study has the following limitations:
1. A large percentage (52%) of the student responses were classified as
inconclusive in terms of misconceptions. The category of “inconclusive” was not
a part of the original classification, but I was forced to include it after it became
clear to me that many responses that were incorrect lacked sufficient evidence to
be coded a misconception. I do not contend here that students who produced
these responses did not have a misconception inherent to their explanation, but
155
merely that there was a lack of evidence in the explanation for me to infer that a
misconception existed. Many cases which fell into this category suggested poor
readability of the question as student responses were not focussed on what was
demanded in the question. A possible improvement regarding the classification of
inconclusive student responses may be to add an extra category, such as the
category of “non-explanations” as identified by Gilbert et al. (1998a). Perhaps in
future studies a variety of explanation frameworks could be fused to gain an even
greater degree of inclusivity.
2. This study focussed on the Physics content area and identified five common
misconceptions in the mechanics and electricity content areas. The questions in
the examination paper regarding mechanics and electricity yielded more
descriptive answers than those regarding optics. The strength in this focus was
that it allowed for greater depth of analysis. However, the limitation is that it
provided no information regarding optics.
3. The interview sample size of ten students and two teachers drawn from only one
school is too small for the generalisation of results. A larger sample in terms of
schools, students and teachers involved could have given a clearer picture of the
misconceptions held by SA grade 12 Physics students. Also, the questions asked
during the teacher interviews could have focussed more on the teachers’
knowledge of the specific misconceptions held by their students. Also, according
to Henning et al. (2004) the validity of qualitative research studies, such as this
one, can be improved by asking the students and teachers in the interview
sample whether the findings make sense to them
5.5. RECOMMENDATIONS FOR FUTURE STUDIES
Over the past decade there have been numerous studies regarding misconceptions in
Physical Sciences. However, teacher and student awareness of misconceptions
remains lacking and misconceptions seem to persist despite attempts at remediation.
Hence, the domain of student misconceptions requires further investigation. Future
studies need to focus on further identification of specific misconceptions and their
156
sources, especially in fields such as optics, which are new to the SA curriculum. It is
also important to conduct further research using interview data as this allows the
researcher to probe for more in-depth information regarding student understanding, and
allows the student more time to express and reflect on their conceptions. Research on
conceptual change has also received much attention, however, these new teaching
strategies need to be tested and further developed in SA classrooms. This study
commented on the serious language barriers which are a source of many
misconceptions, hence it is vital that future studies investigate teaching strategies to aid
students with language barriers.
5.6. SUMMARY
In this study I set out to identify the types of explanations and misconceptions
constructed by Physics students and the relationship between student explanations and
misconceptions. I have shown that SA grade 12 students perform poorly in explanation-
type questions and construct predominantly genetic and mechanical explanations.
These explanations reveal misconceptions about what happens to objects in certain
situations as well as misconceptions about how physical properties affect what happens
to objects. I have also shown that students co-construct misconceptions during their
interaction with family, peers, teachers and learning material. Other sources of
misconceptions are language barriers, which are particularly prevalent in SA schools,
and a misplaced focus of assessment on quantitative problem-solving. There are other
factors that influence the construction of misconceptions, factors such the learning
environment and motivation of students. There is a need for the implementation of
teaching strategies that focus on greater depth in conceptual understanding, teaching
strategies such as qualitative discussions, writing activities, conceptual mapping and
more effective practical investigations. However, in order to enable the implementation
of such conceptual change strategies the curriculum needs to be narrowed down to
allow for more depth in understanding and assessment needs to include more
qualitative explanation-type conceptual questions.
157
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Appendix A
Ethical Clearance from UJ
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Appendix B
Approval form to conduct research from Department of Education
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Appendix C
Permission letter to conduct research from Department of Education
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Appendix D
Letter of consent to school principal
45 Sable Mansions Mooikloof Ridge Moreleta Park 27th January 2009
To the principal, HOD of Sciences and the grade 12 Science teacher Requesting permission to involve your Science students and Science teacher in a research project. I am currently conducting a study on student misconceptions in the 2008 grade 12 National Senior Certificate Physics examination, as part of my Masters studies. In order to construct a better understanding of these misconceptions it is necessary for students, participating in this study, to answer a worksheet which contains nine explanation-type questions from the 2008 grade 12 National Senior Certificate Physics examination. This worksheet may be completed during any Science lesson, under test conditions, to allow students the opportunity to think about their answers carefully. Thereafter I will mark the worksheets, identify the common misconceptions and then ask about 10 students that hold these misconceptions to participate in an interview of approximately a half an hour each. I would also need to interview the grade 12 Science teacher, as she may have valuable information regarding the misconceptions that her students hold. I would like to conduct this study at your school at the start of the third term. If you agree to allow me to involve your students and science teacher, I will request written permission from the parents and students to participate voluntarily and anonymously. In a letter requesting their participation, I will explain the benefits of participation to the students. Such benefits include the opportunity to practice typical exam questions and receive valuable feedback regarding personal misconceptions that could affect their performance in their final examination. I am also in the process of gaining permission from the Gauteng Department of Education to conduct this research. I hereby request your permission to involve your Science students and Science teacher in this research project. Kind regards Celeste van Niekerk ________________________
Permission granted/not granted
Concerns regarding participation: ___________________________________________________________________________________________________________________________________________________________________________________________________________________________
Signed by: _________________________________________________________________________
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Appendix E
Letter of consent to science teachers
P.O. Box 174 Menlyn 0063 Cell: 082 688 0834
______________________________________________________________________ TO: The Science Teachers FROM: Celeste van Niekerk RE: Request to conduct research DATE: 29 June 2009 ______________________________________________________________________ The purpose of this letter is to request permission to determine your opinion regarding the extent to which student misconceptions are prevalent in your classes, possible sources of misconceptions and the strategies that you are using to address these misconceptions. It would be appreciated if you could participate in a one-to-one interview in my research study. Please note that you are at liberty to withdraw from this study at any time, without penalty or pressure from me, as the researcher, to provide reasons. In this regard, I will undertake to ensure that participating in this study does not disadvantage you. It is also my belief that there are benefits for you. Your input will contribute to making teachers more aware of the types of misconceptions and sources of misconceptions that students struggle within their Physics exams. It will also be a valuable opportunity to reflect on teaching strategies that are useful to address these misconceptions. Please note that all information supplied will be treated with confidentiality and outcomes of the research will be made available on request. Tape recordings/data will be kept under lock and key and will be destroyed after completion of the research study. Your cooperation and time is highly appreciated. Yours in Education _______________________ _________________________ Celeste van Niekerk Dr U Ramnarain Researcher Supervisor ---------------------------------------------------------------------------------------------------------------- CONSENT
I, _________________________________________________ will participate in the study and give consent that the interview may be tape-recorded. __________________________________ _____________________ Signature of participant Date
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Appendix F
Letter of consent to parents/guardians
45 Sable Mansions
Mooikloof Ridge
Moreleta Park
22nd
July 2009
TO: Parents/guardians of the grade 12 Physical Science students
FROM: Mrs Celeste van Niekerk
RE: Request to conduct research
DATE: 22 July 2009
The purpose of this letter is to request your permission to involve your child in my research study. The grade 12 students of 2008 were the first group of students to write a national examination on a curriculum which is underpinned by outcomes-based education. The performance of students in Physical Sciences was poor. Of the 218 156 students that wrote the paper, 98 060 students (45% of the total) achieved below 30%, and only 62 530 (28, 7%) achieved 40% and above (Department of Education, 2008). Poor results in science education have often been ascribed to students’ misconceptions. Therefore, a great deal of support and guidance is needed with regard to the identification and remediation of students’ misconceptions in Physical Science. I will be conducting research on the causes of grade 12 students’ misconceptions in the Physics exam and on remediation strategies; as part of my Masters Degree at the University of Johannesburg. Research in this area will contribute to improved awareness by teachers and students of common misconceptions that need to be remediated in order to improve student results in Physical Science. The students participating in this study will benefit from this study by getting the opportunity to practice typical exam questions and receive valuable feedback regarding personal misconceptions that could affect their performance in their final examination.
To participate in this study your child will need to answer a worksheet which contains nine explanation-type questions from the 2008 grade 12 National Senior Certificate Physics examination. This worksheet will be completed during a Science lesson next week, under test conditions, to allow students the opportunity to think about their answers carefully. Thereafter I will mark the worksheets, identify the common misconceptions and then ask
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about 10 students that hold these misconceptions to participate in an interview of approximately a half an hour each.
Please note that students are at liberty to withdraw from this study at any time, without penalty or pressure to provide reasons to me, as the researcher. In this regard, I will undertake to ensure that participating in this study does not disadvantage the participants. All the information supplied will be treated with confidentiality and outcomes of the research will be made available on request. Data will be kept under lock and key and will be destroyed after completion of the research study.
Should you have any queries or comments regarding this research study, you are welcome to make contact with me at 082 688 0834. Your cooperation is highly appreciated. Yours in Education
CELESTE VAN NIEKERK DR U RAMNARAIN
Researcher Supervisor ----------------------------------------------------------------------------------------------------------------------
CONSENT REPLY SLIP (Please return this slip to your Science teacher by Monday the 27th July) I, ________________________________________________________, the parent/guardian of ________________________________________ give my consent that he/she may participate in the study and that the information may be used confidentially for research purposes.
___________________________ _____________________
Signature of parent/guardian Date
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Mmmm Science
Research????
Appendix G
Letter of assent to students
Dear student You are kindly requested to complete a Science worksheet during one of your Science lessons next week. The worksheet consists of nine explanation-type questions which were taken from the 2008 grade 12 National Senior Certificate Physics examination. The aim of the worksheet is to identify possible misconceptions that you and ultimately other students may have regarding these typical Science exam questions. The ultimate aim of the research study is to make teachers aware of what misconceptions Science students are struggling with. It will take approximately 30 minutes to complete the worksheet and it should be completed during class under supervised examination conditions. Afterwards I will mark the worksheets and give you feedback about any misconceptions that you may have. The worksheets will not be used by the school for any form of assessment and you are not required to study anything beforehand. I will then identify a few students to conduct an interview with so that I can make sure that I understand your answers and possible misconceptions. I assure you that your identity and your responses to the worksheet will be treated as CONFIDENTIAL at all times and that it will NOT be made available to any unauthorized user. Please note that you are at liberty to withdraw from this study at any time, without penalty or pressure from me, as the researcher, to provide reasons. In this regard, I will undertake to ensure that participating in this study does not disadvantage you. Should you have any queries or comments regarding this research, you are welcome to contact me via your teacher. Your cooperation is highly appreciated. Yours in Education CELESTE VAN NIEKERK Researcher ----------------------------------------------------------------------------------------------------------------------
CONSENT REPLY SLIP (Please return this slip to your Science teacher by Monday the 27th
July) I, ___________________________________________________, the student have read and understand the aims of this research study and agree to participate in the study. ___________________________ _____________________ Signature of student Date
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Appendix H
2008 NSC Physics examination
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Appendix I
Possible answers for the 2008 NSC Physics examination
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Appendix J
Pre-interview test
Grade 12 Physics Worksheet.
Instructions
Read each of the nine questions carefully and then write down your answer as
thoroughly as possible. Take time to write down everything that comes to mind
regarding the answer to the question. None of the questions involve calculations, they
are all questions that require you to explain or describe something.These questions are
not for assessment purposes, they will be used to find out why you think that your
answers could be correct.
Question 1
A circuit is connected as shown below. The resistance of R, which is connected in
parallel with the 10 Ω resistor, is unknown. With switch S closed, the reading on
voltmeter V decreases from 45 V to 43,5 V. The internal resistance of the battery is 0,5
Ω.
How will the reading on voltmeter V change if resistor R burns out? Give a reason for
your answer.
Question 2
A coil is rotated anti-clockwise in a uniform magnetic field. The diagram below shows
the position at the instant the coil lies parallel to the magnetic field.
What type of generator is illustrated in the diagram? Give a reason for your answer.
229
Question 3
An ink-jet printer makes use of the electric field between two oppositely charged parallel
plates to control the position of an ink drop on paper.
In the diagram below, the generator (G) of the printer shoots out ink drops that are
charged in the charging unit C. The input signal from a computer controls the charge
given to each ink drop. P is a negatively charged ink drop.
Is plate B negatively or positively charged? Give a reason for your answer.
Question 4
A helium-neon laser emits red light that passes through a single slit. A diffraction pattern
is observed on a screen some distance away from the slit.
4.1. Briefly describe the pattern that will be observed on the screen.
The single slit is replaced with a double slit.
4.2 Name ONE similarity and ONE difference in the pattern observed when the
single slit is replaced with a double slit.
4.3. Will this pattern be observed if the laser is replaced with a light bulb? Give a
reason for your answer.
Question 5
It is common practice to connect many appliances to a multi-plug. Modern types of
multi-plugs have a cut-off switch built in. Using principles in Physics, explain clearly why
this cut-off switch is important.
230
Question 6
Learners investigate the conducting ability of two metal wires P and Q, made of different
materials. They connect ONE wire at a time in a circuit as shown below.
The potential difference across each wire is increased in equal increments, and the
resulting current through these wires is measured. Using the measurements, the
learners obtained the following sketch graphs for each of the wires.
Which one (P or Q) is the better conductor? Explain your answer.
Question 7
A fully automatic camera has a built-in light meter. When light enters the light
meter, it strikes a metal object that releases electrons and creates a current.
The intensity of the incident radiation on the metal plate is increased whilst
maintaining a constant wavelength of 200nm. State and explain what effect
this change has on the following:
5.1. The energy of the emitted photo-electrons
5.2. The number of emitted photo-electrons
231
Question 8
The diagram below represents how water is funnelled into a pipe and directed to a
turbine at a hydro-electric power plant. The force of the falling water rotates the turbine.
Each second, 200 m of water is funnelled down a vertical shaft to the turbine below.
The vertical height through which the water falls upon reaching the turbine is 150m.
NOTE: One m³ of water has a mass of 1000 kg.
Assume that a generator converts 85% of the maximum kinetic energy gained by the
water, as it falls, into hydro-electricity. Explain what happens to the 15% of the kinetic
energy that is NOT converted into electrical energy.
Question 9
The most common reasons for rear-end collisions are too short a following distance,
speeding and failing brakes. The sketch below represents one such collision. Car A of
mass 1000kg, is stationary at a traffic light, and is hit from behind by Car B of mass
1200kg, travelling at 18m. . Immediately after the collision Car A moves forward at
12m. .
9.1. Modern cars are designed to crumple partially on impact. Explain why it may
NOT be valid to assume that linear momentum is conserved in accidents such as
the one described above.
9.2. A traffic officer appears at the scene of the accident and mentions the dangers of
a head-on collision. He mentions that for cars involved in a head-on collision, the
risk of injury for passengers in a heavier car would be less than for passengers in
a light car.
Use principles of Physics to explain why the statement made by the traffic officer
is correct.
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Appendix K
Extended memorandum for pre-interview test
Grade 12 Physics Worksheet Memorandum.
Instructions
Read each of the nine questions carefully and then write down your answer as
thoroughly as possible. Take time to write down everything that comes to mind
regarding the answer to the question. None of the questions involve calculations, they
are all questions that require you to explain or describe something. These questions are
not for assessment purposes, they will be used to find out why you think that your
answers could be correct.
Question 1
A circuit is connected as shown below. The resistance of R,
which is connected in parallel with the 10 Ω resistor, is
unknown. With switch S closed, the reading on voltmeter V
decreases from 45 V to 43, 5 V. The internal resistance of the
battery is 0, 5 Ω.
How will the reading on voltmeter V change if resistor R burns out? Give a reason for
your answer.
Question 2
A coil is rotated anti-clockwise in a uniform magnetic field. The diagram below shows
the position at the instant the coil lies parallel to the magnetic field.
What type of generator is illustrated in the diagram? Give a
reason for your answer.
233
Question 3
An ink-jet printer makes use of the electric field between two oppositely charged parallel
plates to control the position of an ink drop on paper.
In the diagram below, the generator (G) of the printer shoots out ink drops that are
charged in the charging unit C. The input signal from a computer controls the charge
given to each ink drop. P is a negatively charged ink drop.
Is plate B negatively or positively charged? Give a reason for your answer.
Question 4
A helium-neon laser emits red light that passes through a single slit. A diffraction pattern
is observed on a screen some distance away from the slit.
4.1. Briefly describe the pattern that will be observed on the screen.
The single slit is replaced with a double slit.
4.2 Name ONE similarity and ONE difference in the pattern observed when the
single slit is replaced with a double slit.
234
4.3. Will this pattern be observed if the laser is replaced with a light bulb? Give a
reason for your answer.
235
Question 5
It is common practice to connect many appliances to a multi-plug. Modern types of
multi-plugs have a cut-off switch built in. Using principles in Physics, explain clearly why
this cut-off switch is
important.
236
Question 6
Learners investigate the conducting ability of two
metal wires P and Q, made of different materials.
They connect ONE wire at a time in a circuit as
shown below.
The potential difference across each wire is
increased in equal increments, and the resulting
current through these wires is measured. Using the
measurements, the learners obtained the following
sketch graphs for each of the wires.
Which one (P or Q) is the better conductor? Explain
your answer.
237
Question 7
A fully automatic camera has a built-in light meter. When light enters the light
meter, it strikes a metal object that releases electrons and creates a current.
The intensity of the incident radiation on the metal plate is increased whilst
maintaining a constant wavelength of 200nm. State and explain what effect
this change has on the following:
5.1. The energy of the emitted photo-electrons
5.2. The number of emitted photo-electrons
Question 8
The diagram below represents how water is funnelled into a pipe and directed to a
turbine at a hydro-electric power plant. The force of the falling water rotates the turbine.
Each second, 200 m of water is
funnelled down a vertical shaft to the
turbine below. The vertical height
through which the water falls upon
reaching the turbine is 150m.
NOTE: One m³ of water has a mass of
1000 kg.
Assume that a generator converts 85% of the maximum kinetic energy gained by the
water, as it falls, into hydro-electricity. Explain what happens to the 15% of the kinetic
energy that is NOT converted into electrical energy.
238
Question 9
The most common reasons for rear-end collisions are too short a following distance,
speeding and failing brakes. The sketch below represents one such collision. Car A of
mass 1000kg, is stationary at a traffic light, and is hit from behind by Car B of mass
1200kg, travelling at 18m. . Immediately after the collision Car A moves forward at
12m. .
9.2. Modern cars are designed to
crumple partially on impact. Explain why it may NOT be valid to assume that linear
momentum is conserved in accidents such as the one described above.
9.2. A traffic officer appears at the scene of the accident and mentions the dangers of
a head-on collision. He mentions that for cars involved in a head-on collision, the
risk of injury for passengers in a heavier car would be less than for passengers in
a light car.
Use principles of Physics to explain why the statement made by the traffic officer
is correct.
239
Appendix L
Exemplars of classification-grid data
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Appendix M
Questionnaire schedule for interviews
Teachers:
1. Tell me, in your experience with the Science students in your class, how common
are student’ misconceptions?
2. How do you think students develop misconceptions?
3. From your point of view, what would you say are the main sources of student’
misconceptions?
4. How would you define a misconception?
5. What strategies do you use or have you tried, which may remedy student’
misconceptions?
6. Have you received any training or attended any course or meeting where
student’ misconceptions in Science or strategies for remedying them has been
discussed? Tell me about that.
7. Have you come across any articles on students misconceptions while reading
about Science? Tell me about that.
8. Have you come across any misconceptions in Science textbooks? Tell me about
those.
9. What are the most common misconceptions that you have come across in your
grade 12 students Physics papers?
10. In your opinion would practical work and experiments have any effect on student
misconceptions? Tell me about that.
11. Do you think that language would have any effect on student misconceptions?
Tell me about that.
12. Do you think the language of Science terminology would have any effect on
student misconceptions? Tell me about that.
244
Students:
1. When a heavy vehicle collides into a lighter car the passengers in the lighter car
are likely to be injured more seriously. Tell me from a scientific point of view why
this happens.
Why do you think that cars with a greater mass exert a greater force on lighter
cars during a collision?
Where do you think you got the idea that heavier cars exert a greater force on
lighter cars during a collision?
Explain to me what impulse is.
Explain the difference between weight and mass.
Newton’s third law states that for every force there is an equal but opposite force.
How would you apply this law to the heavy and light car that collided head- on?
During a head-on collision both the lighter and the heavier car experiences a
deceleration. Do you think the cars experience the same acceleration? Explain
why/why not.
Where would you say you got most of these ideas on momentum? Where else?
In certain collisions linear momentum isn’t conserved. When would you say does
that happen?
Explain why you think momentum isn’t conserved when that happens.
What would you say is the difference between an elastic collision and an inelastic
collision?
2. At a hydro-electric power plant the generator converts about 85% of the water’s
kinetic energy into hydro-electric energy. What happens to the other 15% of the
kinetic energy?
Explain what you mean when you say the energy is lost. Where would you say
you got the idea that the energy is lost? Does this idea of lost energy match up
with the law of conservation of energy? Why/ Why not?
3. What happens to the voltmeter reading if resistor R burns out?
245
Tell me more about why you think the voltmeter reading will increase if there is
less resistance in the circuit?
What potential difference would you say the voltmeter measures when it is
connected in the position shown in the diagram?
What does a voltmeter actually measure? What are volts?
Tell me more about why you think the circuit’s resistance will be less when
resistor R burns out?
4. What type of generator is illustrated in the diagram?
Tell me more about the difference between an ac and a dc generator.
Is there a difference between a split-ring and a slip-ring? What is the difference?
Where do you find a split-ring and a slip-ring?
5. Modern types of multi-plugs have a cut-off switch built in. Why are they so
important?
What do you think could cause the power to get too intense? What exactly is
power?
Explain to me in more detail why the components get hot.
Explain how the components take more volts.
Tell me, what are volts?
246
When you connect components into a multi-plug, would you say they are
connected in series or parallel? Explain your answer.
If the components are connected in parallel in a multi-plug, then what happens to
the resistance as you add resistors in parallel?
What happens to the current in the circuit if the resistance decreases?
6. What is the charge on plate B if the ink droplet in the diagram is negatively
charged? Explain your answer.
Tell me more about how this works.
7. When a laser emits red light that passes through a single slit, a diffraction pattern
can be seen on a screen some distance away from the slit. What does the
diffraction pattern look like?
Tell me more about what it will look like. What colour?
Have you seen a diffraction pattern? Where?
If the single slit is replaced with a double slit, what similarity will you notice
between the patterns formed?
If the single slit is replaced with a double slit, what difference will you notice
between the patterns formed?
Have you seen a double split interference pattern? Where?
What will you observe if the laser is replaced with a light bulb?
Are there any other differences you can think of between the laser and a light
bulb?
247
8. The conducting ability of two metal wires P and
Q was tested, by measuring the current running
through the wires and the potential difference
across the wires. Results as in this diagram
were obtained:
Which conductor is a better conductor?
Tell me more about why having the highest potential difference would make P
the better conductor.
How would P get a higher potential difference across it?
What would you say have conductivity and current got to do with one another?
Explain to me what the gradient of this graph represents.
9. A fully automatic camera has a built-in light meter. When light enters the light
meter, it strikes a metal object that releases electrons and creates a current.
What happens to the energy of the emitted photo-electrons if the intensity of the
incident radiation is increased, whilst maintaining a constant wavelength?
Tell me why you think the energy of the photo-electrons will increase if the
incident radiation increases?
What do you think it means when the wavelength of the radiation stays constant?
What do you think increases when you increase the incident radiation without
changing the wavelength?
What would you say happens to the number of photo-electrons emitted when the
incident radiation increases?
Have you seen a light meter or photo-electric cell? Where? Where would you say
did you get most of your ideas about the photo-electric effect?
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Appendix N
Transcripts of student interviews
N1: Interview with the first student on 12/08/2009 at 11h00-11h15
Researcher: In your worksheet over here, you wrote that: “wire P will be a better
conductor, because it provides the highest level of potential difference.”
Can you tell me more about why you think that because wire P has a
higher potential difference that will make it a better conductor?
Student 1: I have no idea, honestly mam I was guessing on that because I do very
badly in what's its name.
Researcher: Electricity?
Student 1: Yes mam, (Pause).
Researcher: OK, but why do you think you guessed that? Why would that be your
guess? When wire P has a bigger potential difference?
Student 1: Ummm, I suppose…
Researcher: Let me show you the circuit again. The circuit looks like this, (showed
learner the circuit on the worksheet) so there’s wire P.
Student 1: Mmm
Researcher: And now you said that it has a higher potential difference, there is the
voltmeter and the voltmeter is giving you that reading. And so you said
that you think that it’s got something to do with potential difference. The
fact that it has a higher potential difference makes it a better conductor.
249
Why do you think you guessed that, do you think there is a connection
between potential difference and being a good conductor?
Student 1: Pause. I have no idea. I think I looked at it and I can’t remember but I was
thinking of... what was I thinking?, Pause, umm what was I thinking now?,
Pause, I figured that if it has a high potential difference then it will have, I
really can’t remember mam.
Researcher: Can you think of the connection between V and A.
Student 1: No.
Researcher: Potential difference and current? Do you know of some relationship
between those?
Student 1: I don’t know…
Researcher: Or an equation between those two?
Student 1: I=V, no, there is a V and a I somewhere, pause isn’t it I=V/R, no, R=, but
then there was no R here so I just figured…
Researcher: So you knew there was some relation there, ok in that relationship there is
R, and here there is no R?
Student 1: Mm.
Researcher: What is the wire?
Student 1: Which wire mam? This wire?
250
Researcher: Ja, that wire. Could that be the R?
Student 1: I suppose because they always draw the resistor like that.
Researcher: Ok, so it could be the resistor. Ok so if it was the resistor, then this V and
R could have something to do with the resistor (finding it very difficult not
to explain it to her, I think I already am). What do you think resistance has
got to do with conductivity? Because here they wanted to investigate
which metal is a better conductor. What has conductivity got to do with
resistance? Because you know that there is a connection here between V
and I and R?
Student 1: MM
Researcher: But they are asking about conductivity, what has conductivity got to do
with resistance? Is there any connection between conductivity and
resistance?
Student 1: Pause, I don’t think so.
Researcher: You don’t think so?
Student 1: Well, conductivity isn’t it like related to electricity, but then this one resists
it, doesn’t it like resist.
Researcher: What is resistance?
Student 1: Resistance? I think like it decreases I wonder a current that flows or
something.
Researcher: So what would you say then is the relationship between conductivity and
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resistance?
Student 1: That they are directly proportional, no no, I wonder, no, ugh, I suppose
that the higher the resistance the less the conductivity (very hesitant).
Researcher: Ok, so in other words you know that if the resistance is high the
conductivity is low.... ok let’s see what else there is, if you now had to
have a look at this graph, what do you think the gradient of this graph
represents?
Student 1: Could it be resistance? Pause. This is I right and this is V?
Researcher: How do you work out the gradient of a graph?
Student 1: Gradient, a change in y over change in x.
Researcher: Ok so it would be?
Student 1: Um, it would be this over that, (pause).
Researcher: Ok and what would that then be?
Student 1: R? No, it can’t be resistance; I think it’s got to do with resistance I’m not
sure.
Researcher: So it’s got to do with resistance? So in a way it is telling you conductivity?
It’s got something to do with that.
Student 1: Why didn’t I think of that?
Researcher: Did you think of the gradient when you answered the question?
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Student 1: Not at all, honestly speaking.
Researcher: You just saw that there were the same values there but you didn’t think of
the gradient?
Student 1: I didn’t and I umm with electricity we haven’t really touched it like the last
time we actually did something extensive on electricity was like in grade 9.
Researcher: Ok, in grade 11, last year?
Student 1: Last year, it was um what is it um self study, I think, because we didn’t
have enough time or something.
Researcher: In grade 11 and you haven’t done it in grade 12?
Student 1: No we haven’t, no yes did we do it?
Researcher: Did you do electricity in grade 12?
Student 1: Yes I think so mam.
Researcher: So you think so, but you don’t remember that much?
Student 1: No.
Researcher: Ok, let’s look at another question. Pause. Ok, let’s look at this one.
Student 1: Ooo, that’s a bad one.
Researcher: The question was: What type of generator is this? And you wrote that:
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“this generator is a split-ring generator.” Why do you think that this is a
split-ring generator?
Student 1: I guessed that maybe, I didn’t know the split ring is in it but it can like turn
or something, I don’t know, I can’t remember. But then, jaaa but then….
Researcher: Tell me about the split-ring.
Student 1: That was the only thing that I actually remembered about generators, oh
and ac conductor, ok, ac conductors or something.
Researcher: Do you think that this is an ac or a dc generator, because those are the
two types of generators that you get? So do you think that this is an ac
generator or a dc generator?
Student 1: I think that it is an ac.
Researcher: Ok, so you think it is an ac generator? What is the difference between an
ac generator and a dc generator?
Student 1: AC is alternate current, changing direct current.
Researcher: And physical differences? How would it do that?
Student 1: Umm. Isn’t it that if you can with this umm split ring I think, if you turn it or
something I don’t know it turns or somehow, something about the
magnetic, I really can’t remember.
Researcher: Something about the magnetic?
Student 1: Magnetic field. I can’t remember.
254
Researcher: You spoke about a split-ring, and you also get a slip-ring, do you know the
difference between slip-rings and split-rings?
Student 1: No mam.
Researcher: Ok, so you wouldn’t be able to tell me where you find a split-ring and
where you find a slip-ring?
Student 1: I would, had I actually studied, but I didn’t.
Researcher: Ok, so you haven’t done this type of question for a while?
Student 1: Since, wow, last term.
Researcher: Ok, umm, let’s look at this other question of yours, this question I think
may be more familiar, I think you did it this year. Ok. This is the one about
the collisions with the two cars. The two cars bumping into one another.
Ok, so the question said: “In certain collisions, momentum, linear
momentum, isn’t conserved”, and then the question asks: “when isn’t
momentum conserved”… and you wrote that: “momentum will not be
conserved in this type of collision because the kinetic energy before the
collision is not going to stay the same as afterwards." Explain why you
think momentum isn’t conserved, when this happens.
Student 1: Because, as some of the energy is lost through sound and when and ja
sound, heat.
Researcher: Ok, so energy is lost in sound and so on, so tell me why if energy isn’t
conserved, why do you think momentum isn’t conserved?
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Student 1: Umm, because there is an external ja it’s not a closed system because
there are external force acting on it (very hesitant). No, no, no I am lying,
oh.
Researcher: You are not actually, say that again.
Student 1: I said something about an external force.
Researcher: What external forces do you think could be acting on those cars?
Student 1: Ah, I wonder is friction an external force? Pause. So there is an external
force? Pause
Researcher: Nod. So the external forces act, that’s why the momentum isn’t conserved.
What have the external forces got to do with energy though?
Student 1: Long Pause. Because isn’t that F=ma, so no no, umm, pause, you said
why is force, what was the question again?
Researcher: What has the force, the fact that there are external forces, got to do with
the energy lost, why is the energy lost when there are external forces?
Student 1: Um, long pause. I don’t know. Pause. This force will cause these things to
move right? And no work don’t know, no, ugh I really …
Researcher: Ok, um just one other thing I wanted to ask, you said that energy is lost
during the collision, because it is changed into heat and sound. Why do
you say energy is lost if it has changed into heat and sound?
Student 1: Yes it is transferred, sorry.
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Researcher: Transferred? To what?
Student 1: Ja, energy can never be lost only transferred into other forms.
Researcher: Ok so you know energy can never be lost, where did you get that idea
from?
Student 1: We learnt it like.
Researcher: So there is a law?
Student 1: Yes.
Researcher: A Science law? Do you agree with that law? Does your everyday
experience match what you have seen in collisions and that the law that
says energy cannot be lost. Do you believe it; do you think that it is true?
Student 1: That energy cannot be lost?
Researcher: Ahaham.
Student 1: I suppose (hesitant) I never really think about it, I’m going to have to think
about.
Researcher: So why do you say it’s lost if you that the Science law says that energy
isn’t lost, you say that it is so easy to talk about energy lost. Why is it so
easy?
Student 1: Cause we don’t see it. We can’t see…
Researcher: You can’t see the heat? Or where it has gone really?
257
Student 1: Yes mam.
Researcher: So that’s why, it’s just a way of talking, that it’s lost, ok. Um there was one
other thing that I was thinking of while you where answering there. Um
when you write your Physics exam, um, when was your last Physics exam
that you wrote? Did you write one in March?
Student 1: I also wrote one in …
Researcher: June?
Student 1: Yes, mam.
Researcher: Do you struggle with the time? Did you finish in time?
Student 1: No.
Researcher: You didn’t finish? (Learner nods) So time was an issue?
Student 1: Yes mam.
Researcher: Because a lot of what you said was correct and you didn’t write it in your
paper. If you had written what you said to me now you would have got lots
more marks. In other words all the answers that were looking for, you
actually know them, but when I asked you to tell me more, explain to me
more then you suddenly said them. Like for example the closed system
that would have been a mark, um I can’t remember now but there were a
few things. Keywords that you said if you had written them you would have
got the marks, so you lost quite a lot of the marks and you actually knew
the stuff but you didn’t write it, do you think it has got to do with the time?
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Student 1: I have a problem, I tend to doubt myself. Like I want to say something and
I try to write it exactly like in the book and if I forget I get blank and then
just move onto the next question, and think I will come back to it.
Researcher: Ok, I think that’s all. When a heavy car collides into a lighter car the
passengers are more seriously injured and you wrote: “the heavier car will
exert a much higher force than the lighter car”, why do you think so, why
do you think that the heavier car will exert a much higher force on the
lighter car?
Student 1: Because it’s mass is greater.
Researcher: Ok and why if its mass is greater will it exert more force?
Student 1: Because the momentum is um directly proportional to the mass and so if
the mass is greater, obviously the momentum is going to be higher, and
isn’t it that F is equal to momentum, so if the momentum is higher than the
force, I don’t know if like it’s there so the force is going to be greater, isn’t
it that the amount of force that it exerts on the small car isn’t it that the
same amount exerts back on the car or something.
Researcher: Ok so now you are saying that it is equal?
Student 1: No no, just that mm ugh, all I know is that the big car is going to hurt the,
it’s going to exert a much greater force than the light car.
Researcher: Where do you think you got the idea that it’s going to exert a bigger force?
Student 1: Umm, because pause, because of the fact that momentum equals mass
times velocity.
259
Researcher: Ok, but if it’s got more mass does that mean it’s got more velocity?
Student 1: Noo, Oooh yeah.
Researcher: Would you say it is from an experience point of view? or from science
lessons?
Student 1: I suppose, I remember mam said something about it.
Researcher: You also wrote that the fact that the stationary car moved also indicates a
greater force by the heavier car, do you think that it is always like that, that
the object that moves is experiencing a bigger force?
Student 1: Yes, cause, I think so, because if like the um the force was the same then
it wouldn’t have moved at all like if you try and push a wall your force is
not big enough so it is not going to move at all.
Researcher: Ok, and what would you say would Newton’s third law work here because
he said that for every force there is an equal opposite force, so when the
two cars hit one another then the force is equal. Does that apply in a
head-on-collision?
Student 1: I think it does apply, I think so.
Researcher: If it applies how come the little car gets hurt more?
Student 1: Stronger materials, I don’t know. (Bell rings)
Researcher: Thank You.
260
Student 1: The crumple zones I suppose.
Researcher: Ok. (The researcher switches off the tape-recorder).
N2: Interview with the second student on 12/08/2009 at 14h15-14h30
Researcher: There we are, (researcher open the learners’ answers to the worksheet)
so how I chose questions, it doesn’t mean that you got the question right
or wrong if I chose the question, it just means that you expressed yourself
and I sort of, it sort of gives me a good understanding of what you are
thinking, but I want to know more. And then also maybe no one else
answered that question so I want all the questions covered. All these
questions come from last years’ Physics paper, ok. So the question that I
want to ask you first is about light. The question says that: “when a laser
emits light through a single slit, then you get a diffraction pattern, and it
can be seen on a screen some distance away from the slit. In your answer
you wrote: “The diffraction pattern consists of many lights, produced on
the medium, when using double slits, one light using the single slit.”
Student 2: Ok.
Researcher: Have you seen a diffraction pattern?
Student 2: Ja, we made a, a small science experiment.
Researcher: Please talk a little louder.
Student 2: We made a small Science experiment, in class and I kind of like remember
a few stuff from xx.
Researcher: When did you do that experiment?
261
Student 2: Um I don’t quite remember, I think it was in March.
Researcher: This year?
Student 2: Ja.
Researcher: Can you tell me more about what it looked like, you said it consists of
many lights, what do those light look like?
Student 2: Ok we used a red laser light, right, so uh, we took paper as the medium
and we put it against the wall and then uh there was a double slit
apparatus and then we light the light through the double slit then it
diffracted, like into I think four lights, four different lights.
Researcher: What colour?
Student 2: It was red.
Researcher: And all the same, all, all the different lights did the whole pattern look the
same?
Student 2: Mm (Laugh)
Researcher: Let’s say I had never seen it, what, you are saying it was a red light, what
did it look like, was it just one blur of red light, or what did it look like?
Student 2: It wasn’t, it was spots.
Researcher: Spots?
262
Student 2: Ja.
Researcher: Ok.
Student 2: It wasn’t a, a, um like a spectrum, like you know, separating all the
colours, it was just …
Researcher: Red spots?
Student 2: Ja.
Researcher: Ok.
Student 2: Showing diffraction.
Researcher: Ok, if the single slit is replaced with a double slit then you get a different
pattern. Ok, um what is the difference between the pattern that you get
when you use a single slit and when you use a double slit? What’s the
difference? Can you remember? Did you do both, the single slit and the
double slit?
Student 2: No, we only did the one slit.
Researcher: Only one slit?
Student 2: Aahah.
Researcher: So you haven’t seen the double slit?
Student 2: No I mean, aah, we did the double slit, but not the single slit.
263
Researcher: So you are not sure, have you seen it in a book or something, the
difference?
Student 2: (Pause) Oh well we, I’ve seen with the water, the double slit with the water
and the single slit with the water, but not with a laser light.
Researcher: Umm, ok then there was another question, the B part of the question, it
said that: “if you replaced the laser with a light bulb …
Student 2: Ok.
Researcher: -and you let the light go through a single slit,
Student 2: Aaha mm.
Researcher: -would you be able to see a diffraction pattern on the paper?
Student 2: I said I don’t think so because it is not strong enough.
Researcher: Ok you said it is not concentrated like a laser. What do you mean by
concentrated?
Student 2: Like a um, how can I explain it, like the strength of the light, you know a
laser you can show a laser and you can see it on the other side of the
room and a light bulb it’s just, aah, you can just light it in a room, one
room, and you can’t see it on the next wall.
Researcher: Ok, and are there any other differences between laser light and a light
bulb, other than that strength that you can think of?
Student 2: Oh, well a laser light just shines on one spot and a light, a light bulb can
264
shine like the whole room, and lighten.
Researcher: Ok. Let us see what other questions you answered. (Pause). The one
about the collisions, with the cars colliding into one another. The question
said: “in certain collisions linear momentum isn’t conserved.” And the
question was: “When is linear momentum not conserved? And you wrote:
“the momentum will not be conserved because the collision may be
inelastic."
Student 2: Aahahm.
Researcher: Why do you think momentum isn’t conserved when a collision is inelastic?
Student 2: Um the difference between the kinetics I think. (Laugh)
Researcher: What’s the difference? (Smile)
Student 2: Mmm?
Researcher: What’s the difference between kinetics?
Student 2: The kinetics, like a, that the kinetic energy, that the a..., the difference in
the mass of the object and ... you know, the velocities and all that, so, so
maybe can’t be the same, can’t you know....
Researcher: What is the difference between an elastic and an inelastic collision?
Student 2: Umm, (you know I can’t remember) (smile) umm, an inelastic collision is,
ok, an inelastic collision is a collision where two objects like collide, uuh
it’s not the same, the, the, amount of force or ah ah or what’s momentum,
the amount of momentum is not the same as when it started and … elastic
265
is when it’s ah like conserved right?
Researcher: What is conserved-
Student 2: (Laugh)
Researcher: in an elastic collision?
Student 2: (Laugh) Ok, um, ……..(pause)…I am nervous.
Researcher: Don’t worry you do not need to be nervous (smile) there isn’t a right or a
wrong.
Student 2: I know what it is, but I can’t explain, I forgot the words.
Researcher: Ok, umm, there was something else; oh there was a B part-
Student 2: Um,
Researcher: Have you thought about it now?
Student 2: I think conservation of momentum is like, how can I put it now, it’s like … I
had it just now, (laugh) ….. xxx
Researcher: Think about it and then we will come back to it. Umm there is a B part of
the question, in the B part of the question there is a traffic officer at the
accident and he says that in head- on collisions, the passengers in the
lighter car usually get hurt more, and you had to explain using Physics
why that is so, why in a head-on collision the passengers in the light car
usually get hurt more. And you wrote: “the driver of the truck will take less
impact because of its size and mass, and the truck will make the car move
266
in the same direction. Tell me more about why you think the truck will take
less impact because of its mass?
Student 2: I think it is because of the material which it is made of, it’s it’s, a car it’s
more like a, I don’t want to say plastic, because there are some parts, like
it’s made out of plastic, more than the truck, you know, it’s not plastic,
plastic, but you know that…, I don’t know that material it’s made off; and
the truck has more weight, you know there’s more stuff put on it and
because of the material as well, so when it collides it will move um the
car… the same direction as the truck was moving.
Researcher: Ok, you said that the truck will take less impact on its materials that it’s
made of, what is impact?
Student 2: Um impact is is the, (pause) for example, a car right, um, put it um,… ish,
ok, …, impact is the amount of force um, an object can take, but then, it
gets destroyed in a kind of way, like when it impacts, yah.
Researcher: So it’s the amount of force that it can take.
Student 2: Yah.
Researcher: Ok, so you are saying the, the, truck can take more force than what the
little car can take. Ok, umm, would you say Newton’s third law applies to a
head-on-collision? Newton’s third law says: “for every force there is an
equal opposite force. Do you think his law works in a head-on -collision,
that the heavy truck exerts the same force as what the light car does?
Student 2: No.
Researcher: Do you think it can’t work there?
267
Student 2: Yah.
Researcher: So … his law that says for every force there is a equal opposite force
doesn’t always work, it’s not really for every force?
Student 2: Maybe it can, but it doesn’t make sense.
Researcher: It doesn’t make sense?
Student 2: Yah.
Researcher: Why do you say that it doesn’t make sense?
Student 2: …Maybe it’s because of the explanation he has made …xx
Researcher: Does it not make sense from your experience point of view?
Student 2: Yah. It doesn’t make logic sense, to me.
Researcher: Ok, …um I was thinking of another place where Newton’s third law is
always used, for example the apple and the earth, the earth pulls the
apple down and the apple pulls the earth up, and Newton’s third law says:
“for every force there is an equal but opposite force, so the earth pulls the
apple down as much as what the apple pulls the earth up. Do you think
that’s right there?
Student 2: Yah it makes sense there that the apples mass is equal upward and
downward, and that the earth’s size has more influence on the gravity of
the, which pulls the apple down.
268
Researcher: So they have the same, there you believe that the forces are equal and
that the reason the apple falls is because the earth’s bigger?
Student 2: Yah.
Researcher: Ok…. Umm. The last question asked about modern multi-plugs, they
have a cut-off switch, you can actually see it over there, that little thing
sticking out. Umm, why is the cut-off switch so important, and you said
that: “the cut-off switch is important because once there is an overflow of
power into one plug and it is damaging your devices it is not
recommended if such a similar thing happens to pull the plug connected
because that can result in your death, because of the voltage power.
Therefore when pressing the cut-off switch it will allow you to remove the
plug, connecting any device, and avoid the fire." Why do you think, what
do you think will cause a overflow of power?
Student 2: I think if you put too many plugs in one, step-up and step-down, lots of
plugs can cause confusion.
Researcher: What is power?
Student 2: The amount of work that can be done.
Researcher: And what is the voltage, power that you wrote about?
Student 2: Electric voltage, human body is, what’s that word, it’s like a conductor as
well, not a weak conductor we can’t survive it, electricity and heat can be
transferred, too much heat causes our death.
Researcher: Are the plugs in the multi-plug connected in series or in parallel?
269
Student 2: Series.
Researcher: Why do you say so?
Student 2: I remember something, it is easier can’t be room in parallel or a house
can’t be in a single row.
Researcher: (The researcher switched off the tape recorder and thanked the learner.)
N3: Interview with the third student on 12/08/2009 at 14h30-14h45
Researcher: In your worksheet you wrote that: “when resistor R in the diagram burns
out, then because the electric line is divided up into parallel line, the
voltage will stay the same, but the current will increase and the heat will
build up”, and the question was: “What will happen to the voltmeter
reading, so you say it will stay the same, but the current will increase and
the heat will build up, ok tell me more, why will the current increase when
the resistor burns out?
Student 3: Because the, in my understanding the resistor doesn’t actually work on
the, well it decreases the voltage but it doesn’t like decrease the voltage, it
just slows down the current so it’s like less harsh power or less, like if you
work on the voltage it wouldn’t be as effective as a circuit unit. So I figured
if it went then the ah, um, the , it went because the heat built up in the first
place, and if it went, then there is like no light bulb or like any other circuit
items to like, um, vent the heat and energy that’s in it. So like the current
would, I think I said, increase, so the current would increase because the
resistor like slows down the current and so if it’s not there it would like
increase the current.
Researcher: So you say that when that resistor burns out there is less resistance, that’s
270
why the current increases?
Student 3: Yes.
Researcher: Ok. Even though it is in parallel?
Student 3: Well, like I figured it is in parallel, like it splits, and if it burns out, then the
electrons would just find another route around, but seeing as it is not split
up any more they would move faster on one leg, like on one wire.
Researcher: How do you add resistors that are in series, let’s say they are a 10 and a
12 ohm?
Student 3: Well I know that if they are in parallel there is a little formula that I can’t
remember now, but if series then I am just going to add them.
Researcher: Ok, so the formula for parallel you can’t remember how that works?
Student 3: Umm you, you, take the ratio between the, the, them and then you add
them in the ratio or something like that.
Researcher: Can you try an easy one for me, let us say that you need to add 2 and 2, 2
resistors of 2 ohms in parallel and you need to add them, can you try and
add them. I can give you the formula, because that is given in the exam,
(researcher writes the formula on paper and gives it to the learner to try
the sum) try and see if you can add those two.
Student 3: (The learner does the sum and gets the correct answer of 1 ohm.)
Researcher: So you get 1 ohm, let me check your sum, yes it is correct, so 2 plus 2 is
1, so what does that tell you about adding resistors in parallel?
271
Student 3: Umm, that the total is a fraction.
Researcher: So it is actually less, if I had one two ohm resistor the resistance would be
two, but if I add another one the resistance goes down.
Student 3: Oh...
Researcher: So that that is quite weird if I have two in parallel and I take away one the
resistance goes from one to two, it actually increases when I take away a
resistor.
Student 3: Oh ja, then the current will decrease.
Researcher: Yes. Ok another question now, the one about the two cars bumping into
one another. The one car is standing at the robot and the other car comes
and bumps into it. The first question says that in certain collisions
momentum isn’t conserved, and then the question is: when is it not
conserved. In your worksheet you said that: "momentum will not be
conserved because energy is lost in the crash due to exchange into heat
and sound." Explain why you think momentum isn’t conserved when that
happens?
Student 3: Well momentum is like the product of mass times velocity, right? And
when it catches the, the, energy, the kinetic energy that the vehicle has,
when it catches it, not a lot, but some of it is lost, due like to conversion
into other forms of energy, um it will have like a small bounce and it will
deform the vehicle. I am not sure what linear momentum is, but I figure
that linear momentum is basically the same as momentum, and when it
like, it will, the energy of the truck would be lower after the crash because
of,...the producers of the cars produce the cars so that they do lose
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energy during the crash, so that the momentum does go down, so it would
go down.
Researcher: So you say that the momentum would go down?
Student 3: Yes.
Researcher: Why do you think that it would go down?
Student 3: Because the, I can put the word impulse there as well because I don’t
know where it goes.
Researcher: Ok.
Student 3: But energy is lost you know and so it has to be lower.
Researcher: Ok, so tell me more about this energy is lost thing, you say that energy is
lost when it is exchanged into sound and heat.
Student 3: Yes, well no the energy doesn’t really disappear, it is converted, but it is
lost from kinetic energy, the actual kinetic energy of the vehicle is lower
after the crash than before the crash, you know.
Researcher: So because it’s changed you say that it is lost?
Student 3: Yes, in terms of kinetic energy.
Researcher: Ok, then in the B part of the question the traffic cop standing there says
that he has seen head-on collisions before and in head-on -collisions the
passengers in the smaller lighter car usually get injured worse and from a
Physics point of view why does that happen? So you (L3) said that “the
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reason it happens is that the light object has little momentum and when it
collides with a heavy object momentum is transferred between them. The
light object with the large momentum will now move at a higher velocity,
so the impulse of such a collision will be also more on a lighter object”.
Tell me why you think the light car has little momentum before the
collision?
Student 3: Um, because it has a low mass and like a light car it’s like a golf ball or
something when you catch it, it doesn’t have a lot of momentum you can
stop it with you hand or so. But when it gets bigger like a truck or so, like
even when you apply full breaks it still takes ten meters or twelve meters
to stop, because the mass is so large.
Researcher: So the little car has low momentum because of its low mass? Does
momentum only depend on mass?
Student 3: Um no, it also depends on the velocity.
Researcher: So if the car had a higher velocity?
Student 3: Then it would also you know have a high momentum, but, I figured that
seeing as it is a small car, small cars usually have small engines as well,
and a small engine can’t really let a small car go faster than a big car.
Researcher: Do you think that a small car could ever have more momentum than a big
car?
Student 3: In some cases yes… extreme cases.
Researcher: Explain to me why you think that the impulse will be more on the light
car?
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Student 3: Because the impulse is like the change in, the change in momentum, from
like before, and a light car will have low momentum before it crashes and
then when it does crash the, the, like energy which is transferred between
the two vehicles will increase its momentum and it will like, the shock will
be large, like the people on the inside will feel like a big force backward
and their necks will hurt or break or whatever, so the impulse, the change
in momentum will like be larger.
Researcher: How do you know that the people in the smaller car will experience a
bigger force?
Where would you say you got that idea from?
Student 3: Because, um, for instance if they crashed into a wall, a big one, not like a
small one, the impulse there will be very large because the wall doesn’t
have crumple zones and the wall would just direct all the energy back from
the car, like and then the car will basically just bounce off the wall, it has
its own small crumple zones, but a lot of bouncing is involved, and so
that’s the same with another vehicle, another vehicle just absorbs more
energy.
Researcher: So the wall would hardly experience any impulse?
Student 3: Um I think the impulse is the same but the wall doesn’t experience it,
because the wall doesn’t, it’s like strong.
Researcher: Ok, so you are saying that the impulse is the same?
Student 3: I think so, yes.
Researcher: Do you think it is the same for the small car and for the big car?
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Student 3: It might be I am not sure.
Researcher: Newton’s third law says that for every force or action there is an equal but
opposite force or reaction, do you think that applies in a head-on collision?
Student 3: Yes.
Researcher: Do you think the force of the big car on the small car is equal to the force
of the small car on the big car?
Student 3: Yes, it should be, I heard an example once where they said that when a
mosquito collides into a car the mosquito experiences the same force as
the car experiences from the mosquito.
Researcher: Do you believe that?
Student 3: I don’t know what they mean by that.
Researcher: Are they going to look the same?
Student 3: No, well, not at all. I don’t know what they mean, that the force will be the
same, because like, like to me it doesn’t make much sense.
Researcher: Ok, so you know the law, that’s why you are agreeing with it, but it doesn’t
make much sense from an experience point of view?
Student 3: Maybe if I had more equipment and stuff to measure it, then it would
make more sense, but from my limited experiences I don’t see it.
Researcher: Ok, thank you. Last question, (pause, while looking up the next question
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that the learner answered). In the hydro-electric power plant, the generator
converts 85% of the water’s kinetic energy into hydro-electrical energy, the
question is: what happens to the other 15% of the water’s kinetic energy
that doesn’t get converted into hydro-electrical energy. You wrote that:
“the other 15% is converted into other forms of energy, and that a
significant amount of energy get’s lost, the 15% of the kinetic energy that
is lost is lost due to friction, which is converted to heat and sound.” Explain
to me more about what you mean by this “energy is lost”?
Student 3: Um, like, when I answer questions like that I use things as a, like certain
parts of the question as a reference for, to my answer, and they asked
about the energy that could be converted into electrical potential energy
and kinetic energy, right? And from the perspective of kinetic energy,
energy is like lost into other forms of energy, you know, and um, like you
can’t really get sound back into kinetic energy, you know, well not with our
current technology, also not with heat, well heat a little bit, but not much,
you can’t get all the heat back into kinetic energy again. So in all essence
it is lost, but the energy still is there it just isn’t in your possession.
Researcher: Ok, there is a whole lot of Science vocabulary that we use, like kinetic
energy and momentum, impulse, sound, heat, etc. Do you think that
talking about energy is lost is Science terminology or every day
terminology? Have you seen it in textbooks or do you use it in the Science
class? Where would you say that wording came from?
Student 3: Well in Science class and the books and stuff, they never use it, they try
and steer us away from the term that it is lost, they try to tell us that it is
not lost, it is just converted and so forth, but for me to use, like, layman’s
terms and to explain the science behind it, to understand it better, I try to
explain it in things that are easy to understand, like lost and not converted.
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Researcher: Ok, thank you, and then how would you say does this idea of lost energy
match up with the conservation of energy?
Student 3: Um…
Researcher: Are you familiar with the law of conservation of energy?
Student 3: I think I know it, but …
Researcher: What do you remember about it?
Student 3: That in a closed system, I think it is a closed system, it’s a closed system,
or it’s a bouncy ball thingy, um in that system, it, it, if there is no friction
and stuff, then it would be conserved, right? But that can’t happen, like
you can’t have a closed system you know, because um normal things
can’t do that like you can’t get a little box and catch two things in there,
because something will happen, you know, it will absorb some energy.
Researcher: Thank you, that is all that I want to ask you, do you have any questions?
Student 3: No.
N4: Interview with the fourth student on 13/08/2009 at 11h00-11h15
Researcher: In your worksheet you wrote that: “this generator is a dc generator,
because of its slip rings.” Tell me more about the difference between an
ac and a dc generator.
Student 4: Ok, I don’t know. Um, ac, am I right, ac generators, …, dc generators use
electricity to create mechanical energy, I think, and ac generators, …, yah,
use mechanical energy to create energy, I think, I am not sure, cough, so
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what I think mam, is that because an ac generator is slip ring and a dc one
is, no a dc one is slip rings and an ac one is split rings, that’s what I mean.
Researcher: Would you say these in the diagram are spilt rings or slip rings?
Student 4: Slip.
Researcher: Have you done an experiment in the class, where you have built one or
have you seen an ac or dc generator?
Student 4: Experiment no; it’s what I saw from the textbook, slip rings...
Researcher: So pictures?
Student 4: Yes.
Researcher: The next question that you answered was the one about the cut-off switch.
These multi-plugs like this one over here, (researcher points to the nearby
multi-plug) has got a cut-off switch.
Student 4: Ok.
Researcher: So the question on the worksheet said: “why is the cut-off switch so
important?” You wrote that: “The cut-off switch stops the flow of power,
before anything harmful happens, because of the power getting too
intense.” What do you think caused the power to get too intense?
Student 4: (Pause). What caused the power to get too intense? Pause. Maybe
electric shortages or high voltage in the house system, I’m not sure, jah,
pause.
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Researcher: Ok, what exactly is power?
Student 4: Pause, well I think power is electricity and power is, pause, the ability for
us humans to live, the means to produce light, to see in the dark, to to
make food, yah, basically means of living.
Researcher: Ok, and then you said: “the cut-off switch switches off the power before
anything harmful happens”, what do you think causes the components to
get hot?
Student 4: The components to get hot? Umm. (Long Pause). The electricity, I think it
is the electricity, the flow of electricity. When not a specific amount is given
to it, when more than a specific amount is given to it then it gets hot.
Researcher: What do you think happens when I keep adding plugs, like that one can
take five plugs, but because I want more things in, I put a double adaptor
in, with more plugs, what do you think happens then, when I keep adding
plugs to that multi-plug?
Student 4: Well you are using more energy (voice very soft).
Researcher: Using more energy? (Verifying what I heard).
Student 4: I think you are using more energy than what the plug can really … give.
Researcher: And how would you say are those components connected? Are they
connected in parallel or in series?
Student 4: Think series, series.
Researcher: In series?
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Student 4: Series.
Researcher: If they are connected in series, what will they do to the total voltage that
the plug is giving them?
Student 4: I am not sure.
Researcher: Ok, one last question. The question about the car accident, where the one
car drives into the back of the other car at the robot, and the question
says: “when a heavy vehicle collides into a lighter car, the passengers in
the lighter car are more likely to get hurt”, and then you need to explain
why. In your worksheet you wrote that: “the heavier car has more weight,
thus resulting in the passengers in the lighter car having more injuries."
Tell me why do you think the weight of the car will cause more injuries?
Student 4: Umm, weight of the car, because, the weight of the car influences like the
force that the car exerts, so if a car is moving at a certain speed, and then
the lighter one is also moving at a certain speed too, then the, the, heavier
car tries to brake, it’s going to take longer for it to brake, because of all of
the weight on it than the smaller one, so then the heavier one is going to
exert more force than the smaller one, That’s why the smaller one has
more risk of getting injured than the heavier one. Force and the weight,
yah (very softly).
Researcher: Ok, what is the difference between weight and mass?
Student 4: Ok, weight and mass. Pause. Weight, pause I don’t know, don’t know, the
mass…
Researcher: Do you know what mass is?
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Student 4: The mass of the truck. Pause. 9,8 I think.
Researcher: Ok, what is your mass, for example?
Student 4: The one I measure on the scale? Cause that’s weight. Mass, (pause).
Researcher: When you get on the scale, what is the unit?
Student 4: (Pause). Won’t it be kg?
Researcher: Kg, so would kg be the weight?
Student 4: Pause. Think weight.
Researcher: Weight?
Student 4: Weight.
Researcher: That is all I would like to ask you, are there any questions that you would
like to ask?
Student 4: Yes mam.
Researcher: What would you like to ask?
Student 4: It’s about, cause mam gave me this question paper, (he looks through the
worksheet), it’s about these questions about current and dc generator, in
class we don’t do much exercises on them.
Researcher: Exercises or experiments?
282
Student 4: Well experiments, the last time I did experiments on this was in grade 9,
what do you call, circuits and globes, and I don’t have, grade 9’s quite a
long time back compared to matric, it’s like three years back, and my
memory is kind of vague. So, could we like do some more, could as like in
chemistry when we do something we do an experiment to see what
happens, so that when we go and write it, the paper, we already know
what’s going to happen, how this reaction is going to be.
Researcher: It, is definitely true that we need to do more experiments, as a teacher
know the reason that we don’t, is time, we just run out of time, there is so
much that we still need to do, we always run out of time, so at the end of
the day, that is why we just try to get through the theory, even though we
know that you have to do the practical to be able to understand it, but
sometimes, you know, it’s the whole issue of time, so you don’t know what
is going to be the best , so in the end it is a judgment call, because you
need to do both, so you have to do the experiments, and you have to do
the theory, but then sometimes you think that because you have done the
experiments in grade 9 and now because you have to get the theory done,
and yes time is a very big issue. It’s unfortunately the problem, is the time.
N5: Interview with the fifth student on 13/08/2009 at 11h15-11h30
Researcher: This question asks: If R burns out, what happens to the voltmeter reading?
You said that: “When resistor R burns out, then the internal resistance will
decrease because there will be one less resistor working, so the voltmeter
reading will increase.” Explain to me why you think that when the R burns
out the internal resistance will decrease?
Student 5: Because then there is one less resistor. If there is less resistance, then the
current flows more.
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Researcher: Let’s move on to another question, there was a question about a cut-off
switch. In these multi-plugs there is a little cut-off switch, and the question
asks why the cut-off switch is that important, and you said: “the cut-off
switch prevents a power surge from damaging appliances and prevents
extra voltage from going through," what do you think would cause the
power to surge in the first place, to get too intense?
Student 5: Ah, pause. Lightning, or, pause. Or just if the power station is just, its
voltage is too high, or maybe if the like the transformer it is not functioning
or something.
Researcher: Ok, and what exactly is power, when there is too much power?
Student 5: Umm, pause, I usually see it as a, like too much voltage.
Researcher: Too much voltage?
Student 5: Ja.
Researcher: So the voltage increases?
Student 5: Mmm.
Researcher: Would you say those (researcher points to a multi-plug) plugs are
connected in series or parallel?
Student 5: Umm, pause. The plugs connected to the appliance?
Researcher: Yes, so basically the appliances, are they connected in series or in parallel
in there?
284
Student 5: Series.
Researcher: In series?
Student 5: Mm.
Researcher: Ok, last question, just one more. (Pause, while the researcher finds the
next question that the learner answered very expressively.) The collision
one, the car comes from the back and hits into the car at the robot, and
the question says in certain collisions linear momentum isn’t conserved,
when is it not conserved? And you wrote: "Momentum won’t be conserved
as the car’s shape will be permanently changed", explain why you think
the momentum isn’t conserved when that happened?
Student 5: ..Umm, because if it was conserved then the momentum after the collision
will still be equal to the momentum before the collision, and obviously
because there is change in form and heat and whatever, then obviously
momentum was lost.
Researcher: Ok, ah, you also wrote that momentum will be transferred to heat and
sound, like you said now, explain why you think momentum can be
transferred to heat and sound?
Student 5: Why?
.
Researcher: Auuh. Why do you think momentum can be transferred to heat and
sound?
Student 5: Umm.. I don’t really think it is the momentum I think it is the energy, the
kinetic energy.
285
Researcher: Ok, and then they asked: “When a heavy vehicle collides into a lighter car,
um, have I got your answer here ... yes, when the heavy car collides,
afterwards a traffic cop standing there says if a heavy car collides head-on
with a lighter car, the passengers in the lighter car are more likely to get
injured, from a scientific point of view why do you think this happens?
Student 5: Um…um well the heavy car has more mass so (long pause) um … and
also it won’t be, um like the lighter car has more, the chance of being like
hit to the side or something, because it’s lighter, while the heavier car is
more stable on the ground, because it is more heavier, and um,…, it’s
momentum should be actually higher because it has a higher mass, even
if they are travelling at the same speed, the truck still has more
momentum, so, ..
Researcher: ok, thank you very much, that’s it, all the questions, you did really well, do
you enjoy Science?
Student 5: Ja I do.
Researcher: Ok, obviously, you didn’t do as well as you normally do, because it only
was the explanation questions, and most kids do better in the sums,
surprisingly. Are you going to study something in Science next year?
Student 5: Nah.
Researcher: What are you going to do?
Student 5: BComm. Accounting.
Researcher: Aah, money, money, money, (laugh). Thank you very much.
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N6: Interview with the sixth student on 13/08/2009 at 11h30-11h45
Researcher: Ok, so the first question I want to ask you about is this question about the
conducting wires, P and Q, so the question says you have two conducting
wires P and Q and you want to know which one is the better conductor. So
you put them in a circuit, you connect a ammeter near them and you
measure the current that is running through the two wires, and you
connect a voltmeter over the wire, to measure the potential difference
across the wires, and then you plot the data and this is the data that you
get (pointing at the graph on the worksheet), and from that data which
conductor is a better conductor, and why-y, how do you know which one is
a better conductor? Ok, you wrote: “wire P is a better conductor, because
it is at a higher potential difference than Wire Q.” Tell me more about why,
uhh, the higher potential difference would make it a better conductor. Why
do you think it works like that?
Student 6: Um... because, because of the high voltage the condu- um. I don’t really
have a reason for xx
Researcher: Why do you think you guessed that?
Student 6: Umm ... for some reason I think when something has the potential the high
potential difference it has the better conductor.
Researcher: Ok, what is potential difference?
Student 6: It’s the voltage of the umm … conductor or ...
Researcher: Ok, and what is voltage?
287
Student 6: Um, the measurement of umm xxx …aah …umm …can’t really think what
that is now um (pause)
Researcher: Ok, that’s fine. .. What do you think the current has got to do with the
conductivity?
Student 6: Uum that’s what the amount of... energy uh like flow of xxx ah ... what’s
the question again? (Smile)
Researcher: What is current, and what has it got to do with conductivity? Why do you
think they measured the current?
Student 6: I’m having such a blank now...
Researcher: It is there; somewhere, just think about it, what do you know about
current?
Student 6: … I know it has to do with the flow of electrons and all that xxx (Pause)
Researcher: Ok, so it’s got to do with the flow of electrons, so how would that affect the
conductivity?
Student 6: Um, the...actually if it has more currency it will be more conductive
because more electrons flowing -
Researcher: And which one -
Student 6: which would make it easier to -
Researcher: which one looks like it’s got more... current flowing through it?
288
Student 6: Um wire Q, that’s my answer but xxx (learner thinks about it)
Researcher: What do you think, now they have got both here, so they actually want you
to think about both of them, what do you think the gradient of this graph
would be?
Student 6: (long pause)
Researcher: Do you know how to work out the gradient?
Student 6: Yeah, that’s the difference in y over the difference in x.
Researcher: So what would it be for this graph?
Student 6: Um (pause) for the both?
Researcher: Yah, for either of them.
Student 6: Um (pause) I said wire Q’s gradient xx one…
Researcher: In terms of current and potential difference?
Student 6: Um, the current is more to the current (higher) and... wire P has more
potential difference so the (valence) is... lower or um nee I kan dit nie in
Engels sê nie.
Researcher: Jy kan dit in Afrikaans sê.
Student 6: Um, dit is minder (pause) um .. styg minder (pause)
Researcher: Ok
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Student 6: (kan nie help met die woorde nie)
Researcher: Ok ...kom ons kyk na ander vraagie.. antwoord jy gewoonlik in Afrikaans
of Engels?
Student 6: Uum, ek antwoord in engels, maar ons het eintlik tot in graad 10 in
Afrikaans geantwoord, partykeer dan sit mens n .. -
Researcher: Jy weet in die eksamen kan jy in enige iets...
Student 6: Ek weet nie, ons het gevra daaroor toe het hul gese nee as ons in Engels
skryf dan moet ons in Engels skryf.
Researcher: As jy sukkel in die eksamen-
Student 6: So ek weet nie hoe waar is dit -
Researcher: Kan jy enige iets, jy kan deurmekaar ook skryf.
Student 6: Aag ek het nie so groot problem met die (Afrikaans) dit is net partykeer
wat xxx dan het ek nie tyd om als oor te vertaal nie.
Researcher: Maar die merkers sal dit merk, so jy kan dit in engels skryf en dan as jy nie
die woord kan sê nie kan jy deurmekaar skryf, dit (word gemerk.) (Pause
while researcher looks for the next question in the student’s worksheet.)
Ok, hier was die ander ene, ok, uuh, dit was die vraag oor die kar, dit se
as die swaar kar, ah, in n ligte kar in bots dan gaan die mense wat in die
ligte kar sit heel waarskynlik, um, seerder kry, ah, en hoekom is dit so, ah,
ok en toe se jy: “both cars will be moving at a higher speed increasing the
amount of force that will be experienced.” So according to that why do you
290
think if they are both going at a higher speed and are in a head-on
collision, and they both have a bigger force, why do you think the car, the
passengers in the light car will be hurt more?
Student 6: Um, (pause) well the die groter kar sal nogsteeds more force hê want die
massa en die spoed jah ..
Researcher: So dink jy hy gaan meer krag he?
Student 6: Ja di... altwee karre se force sal increase maar die groter vehicle se xxx
sal nogsteeds meer wees as die -
Researcher: Wat sal meer wees?
Student 6: Sy force?
Researcher: Sy impact force?
Student 6: Ja
Researcher: So sal hy die kleiner kar harder slaan as wat die ander kar hom slaan?
Student 6: Ja
Researcher: Ok,..hoekom dink jy so, hoekom sal hy harder slaan?
Student 6: Um.. wel dis groter oppervlakte eerstens wat … teenoor die kleiner kar
wat hy … meer area om te slaan en … as … die massa, as force massa
en accelerasie acceleration is, is sy massa dan meer is, gaan die force
ook meer wees, so (pause)
291
Researcher: En wat van die acceleration deel dan?
Student 6: (Pause) as .. as al twee karre … umm .. soos … word dit .. -
Researcher: Jy sê die swaarder kar gaan meer massa hê so sy krag gaan ook meer
wees, maar die krag is massa en versnelling, soo is jy seker dat sy
versnelling ook meer is?
Student 6: Oo, dit beteken nie dat sy versnelling gaan meer wees nie ,nie
noodwendig nie.
Researcher: Nie noodwendig nie, dan sal dit miskien die krag beinvloed?
Student 6: Nee, dit gaan net die krag beinvloed (dan sal die) krag dieselfde wees as
wanneer hy die stilstaande kar xxxx
Researcher: Ok, en dan ‘n ander ding nê, Newton se derde wet sê dat vir elke krag
wat uitgeoften word, is daar ‘n gelyke teenoorgestelde krag, so sou
Newton se derde wet hierso TEL, as die swaar kar die ligte kar slaan, vir
daai krag is daar 'n gelyke teenoorgestelde krag?
Student 6: …umm (pause) nee want daar .. of daar moet wees want dit maak nie
eintlik xxx maar ek kan eintlik dink waar..
Researcher: Hoekom sê jy daar moet wees, is dit omdat sy wet so sê?
Student 6: …Maar dit kan nie wees nie, want dit is nie geslote die (pause) die
(pause)
Researcher: Ok, so jy dink nie dit gaan daar werk nie?
292
Student 6: Ek dink nie dit gaan werk nie, want … dit gaan nie terug xxx dan gaan die
kar agter in xxx
Researcher: Ok, waar dink jy werk Newton se derde wet wel, wanneer is daar vir elke
krag ‘n gelyke teenoorgestelde krag?
Student 6: Wanneer daar niks anders is wat daarop in werk nie -
Researcher: Soos byvoorbeeld ek en hierdie tafel (researcher pushes her hand down
on the table)?
Student 6: Ja, dit gaan werk -
Researcher: Druk ons mekaar dieselfde hoeveelheid?
Student 6: Ja
Researcher: Ok, hoekom lyk die tafel se, jy weet ‘n tafel het geen misvorming, maar my
hand het, so die effek was nie dieselfde nie, al was die krag dieselfde nê.
Ok, dit is al wat ek wou vra oor daardie ene, nou nog eenietjie,
(researcher looks for the next question that the learner answered on the
worksheet) Wilma was hierso?
Student 6: Nee sy wag buite.
Researcher: Het julle klas nou?
Student 6: Ons onderwyser is afwesig.
Researcher: Daar is nog een vraagie wat ek jou wil vra. (Pause) Oh die lig, dit sê:
“when a laser emits red light and passes through a single slit a diffraction
293
pattern can be seen on a screen some distance away” en die vraag is:
“what does the diffraction pattern look like? En jy het geskryf; “the
diffraction pattern consists of red bars of light with dark bars in between
continuously with a central", dan kon ek nie lees nie, ietsie, “of red light."
Wat het jy gesê is daardie central?
Student 6: The central maximum.
Researcher: Ok, the central maximum of light. Umm. Het jy al ‘n diffraction pattern
gesien?
Student 6: Ek weet ons het, maar ek kan rerig nie meer daardie werk onthou nie,
maar ons het daardie diffraction patterns en daardie goed gesien.
Researcher: Het jul die experiment gedoen.
Student 6: Ja ons het daardie slits gebruik xxx.
Researcher: En jy kan nie mooi onthou hoe het hy gelyk nie?
Student 6: Um, dit was uh, dit was ok daai band bande maar ek kan nie mooi onthou
of dit equal uit mekaar was, of was dit groter spasies en dan kleiner
geword het nie, dit is wat my deurmekaar maak.
Researcher: Ok, en dan as jy die enkel slit met ‘n double slit vervang um hoe lyk die
twee patrone, wat is dieselfde van hulle, kan jy onthou wat was dieselfde
van die twee?
Student 6: Ek dink in ons boeke… (ek kan glad nie onthou nie) smile
Researcher: Ok (smile) So jy kan nie mooi onthou nie, as jy daardie laser sou vervang
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met ‘n gewone lig, .. , sou jy dieselfde patrone sien?
Student 6: Um ja want al wat verskil is die wavelength so nee maar dan sal hy
verander (pause) um (pause)
Researcher: Wat is die verkil tussen ‘n gewone lig bulb en ‘n laser?
Student 6: Um, die wavelength verskil van die (twee)...dit is ..
Researcher: Ok, baie dankie.
N7: Interview with the seventh student on 13/08/2009 at 11h45-12h00
Researcher: I forgot to put the tape-recorder on.
Student 7: Uuu because by crumbling it’s going to go slower, it’s going to lose …
the... if the F = I/g or something (Laugh) I’m not sure…
Researcher: Ok, it’s fine.
Student 7: You are going to lose F so the I will also become (less) but that’s xxx (it
depends)…
Researcher: Ok.
Student 7: I don’t know.
Researcher: Ok, umm, what would you say.... what exactly is an elastic collision, what
is the difference between an elastic collision and an inelastic collision?
Student 7: Ek dink ... I get umm confused between when it is elastic and when it is
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closes the circuit (but) I think elastic is something when something like a
snooker ball almost no momentum is lost there because it is smooth
…and no outside forces … is there to kind of slow it down ..xx
Researcher: Ok, that’s fine and there is another part of the question, the b part of the
question that says: “If two cars collide head-on, there is a light car and a
heavy car colliding head-on then the passengers in the light car will be
less likely to get hurt” … and then you had to say why, why was it like that,
and you said: “ the heavier car will have more momentum so it will keep
going in the same direction but slower , when the lighter cars direction will
change because it’s passenger keeps going the same way so it’s
passengers will experience more force.” For how long do you think the
passengers will keep going the same way, so you said the heavier one is
going to hit then the light one is going to have to change direction it was
going this way (researcher points at the picture of the car on the
worksheet) so it is going to have to change direction, but the passengers
won’t they just keep going forward because of their momentum, for how
long do you think are they going to keep going forward?
Student 7: Just like a few split seconds and then they will be pulled back.
Researcher: Ok so and why will they experience more force?
Student 7: Because they will be moving…it won’t just be force from the front…they
will be moving…in the direction where the force is coming from, so like in
xxx
Researcher: Ok, so because they are going in the opposite direction they are going to
experience even more force.
Student 7: Mm.
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Researcher: Um, Newton’s third law says that for every force there is an equal but
opposite force, do you think that works in a head-on collision like that, will
the force that the heavy truck exerts on the light car, do you think the light
car exerts the same force ?
Student 7: Yes, but the heavier car has even more force.
Researcher: Ok, so the heavier car has even more force?
Student 7: xxx
Researcher: Ok, another question (researcher briefly looks for the next question that
the learner answered on the worksheet.) These multi-plugs (researcher
points at a multi-plug) they have a cut-off switch, why is the cut-off switch
so important? Um, you wrote: “it is important because when current flows
through a conductor, the conductor heats up, if the current is too high, the
wires will burn out.” What causes the current to become too high?
Student 7: The…you mean like if the electrons move it would xxx
Researcher: You said that when the current flows through the conductor the conductors
get hot, and if the current is TOO high then they get too... then the wires
will burn out and that is why you need a cut-off switch. So what would
cause the current to become too high in the first place?
Student 7: If you use too many appliances…in the one like sock-et
Researcher: Mmm. Then the current would get high higher?
Student 7: Yes.
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Researcher: Why do you think it works like that, why do you think the current gets
high? You are right it does get higher, but why?
Student 7: Because it needs to be more places at once.
Researcher: Ok, are those resistors, appliances connected in series or parallel when
you put them in a multi-plug like that?
Student 7: (Pause). Probably series.
Researcher: Why do you think series?
Student 7: (Pause) Because if the..the one appliance breaks the others will still keep
going even though…-
Researcher: So of the one appliance breaks the others can keep going, does that
mean they are in series?
Student 7: …Yes, because then there is no …the circuit isn’t broken there is still
somewhere for the electricity to go ..to the other appliances.
Researcher: Ok, another question, last one. (Researcher looks up next question that
the learner answered on the worksheet). It’s about the laser. The laser
emits a red light and it passes through a single slit and then you get a
diffraction pattern on a screen. What does that diffraction pattern look like?
Ok, you wrote that:”It consists of a bright central band of light with (clear
throat) bands of on both sides, it becomes smaller and dimmer the further
they are from the centre.” What do these bands look like, that become
smaller and dimmer, what do they look like, what colour are they?
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Student 7: Well it’s red and then it’s like black with no colour, and then the red will be
there again but it will be..it wouldn’t be as intense anymore it will be darker
red and darker darker xx
Researcher: Ok, and what do you mean by the bands become smaller?
Student 7: The middle band will be like the bigger piece and space where the red’s
shining and then there will be bigger bands next to it, and then the next
red band won’t be as wide as the middle one and then …(laugh) get
narrower, narrower…
Researcher: It becomes narrower and narrower?
Student 7: Mm
Researcher: Ok, um if they replace the single slit with a double slit, then the pattern
looks different in some ways and similar in some ways. What are the
similarities between the pattern with the single slit and the pattern with the
double slit, what is the same about them?
Student 7: They still have alternating bands of colour and black no colour.
Researcher: And what’s different about them?
Student 7: Um the double slit...the bands will stay the same length apart because of
the wavelength and the same length apart when they cross each other, so
the pattern will just go on …
Researcher: Ok and if you had to replace the laser with a normal light bulb, would you
see those patterns?
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Student 7 .Yes but the light bulb wouldn’t...there…some of the light would be lost
because it’s not like this … straight piece of light, it won’t be as bright, you
are not going to have as much light and it’s going to be a different colour.
Researcher: Ok, thank you, that’s all I wanted to ask. Thank you.
N8: Interview with the eighth student on 14/08/2009 at 11h00-11h15
Researcher: Ok, I am just going to ask you three questions about what you wrote in the
worksheet. The first question is: “A fully automatic camera has a built- in
light meter. When light enters the light meter it strikes a metal object that
releases electrons and creates a current.” And then the question was:
“What happens to the energy of the emitted photo-electrons if the incident
radiation is increased, while maintaining a constant wavelength?” Ok, and
you wrote: “The energy of the emitted photo-electrons increases, as the
intensity increases.” Why do you think that the photo-electrons’ energy,
because they are asking you what happens to the energy of the photo-
electrons when you increase the intensity of the light, why do you think
that the energy of the photo-electrons increases?
Student 8: Ok, honestly, that answer I did not know, so I was like if I write this maybe
I will get one mark or so. I didn’t understand the question, and I didn’t
know the answer at all.
Researcher: Ok, so you can’t think of a reason may be why you guessed that?
Student 8: No. (Laugh)
Researcher: Ok, um. Then there’s another part, ok, what do you think it actually means,
in the question they say: “The intensity of the light increases, but the
wavelength of the light stays the same.” What would you think it means
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when they say the wavelength of the radiation stays constant?
Student 8: Ok, ask the question again, please (laugh).
Researcher: The intensity of the light that hits the light-meter is more, but it’s
wavelength stays the same, what do you think that means, what does it
mean when the wavelength stays the same?
Student 8: (Pause)
Researcher: What is wavelength?
Student 8: (Pause) (I have no idea)
Researcher: If you had to take a guess, if you had to explain it to a friend …what would
you say wavelength is?
Student 8: (Laugh) I don’t know um... The wavelength would be something ok xxxx
(laugh). Inside the light bulb, is this the light?
Researcher: Ja, the light xx
Student 8: Ok, I think the wavelength is the ...amount of time it takes for a person to
see the light on the outside (pause) transmitted from the inside of the light.
(Pause)
Researcher: Ok, and then there was a B part, they said that um: “What would happen
to the number of photo-electrons emitted, if the intensity increased, and
why would it happen?” So you are shining light with a bigger intensity on
the light- meter, what happens to the number of photo-electrons emitted,
and you wrote that: “The number of photo-electrons would increase", um,
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which is right, but you need to explain why, why do you think that number
of photo-electrons will increase when you increase the radiation, why do
you think that it would increase?
Student 8: I just thought that if the radiation increases, then the what is it?
Researcher: Photo-electrons?
Student 8: Ja, the photo-electrons would, you know what, this whole question I just
guessed, so… no I didn’t guess actually, but I just thought that, my brain
just told me I should write that it increased because of the radiation
increasing .
Researcher: Ok, um have you seen a light-meter or a photo-electric cell?
Student 8: MmMm
Researcher: Neither of them, you have never seen a photo-electric cell?
Student 8: MmMm
Researcher: A picture in a book, in your science textbook is there a picture of a photo-
electric cell?
Student 8: Yes, there is.
Researcher: Can you remember what it looks like?
Student 8: No, (smile) (laugh)
Researcher: Can you remember when you did this section?
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Student 8: Last term, no no no no, first term, if I am not mistaken.
Researcher: The first term, ok, (pause) ok, where did you get most of your ideas on the
photo-electric effect, you can’t remember much about the photo-electric
effect, the experiment or anything?
Student 8: No, no, I can’t remember.
Researcher: Ok, thank you, let’s try another question. (Pause) The light one. Um,
“When a laser emits red light and it passes through a single slit then you
get a diffraction pattern on a screen. What does that diffraction pattern
look like?” Ok, um you said: “There will be central maximum, and the rest
of the light will spread out.” Tell me more about what you mean, because
you have got there’s a central maximum, but if I’ve never seen this, I have
no idea what a central maximum is, so I don’t know what it looks like, so
what does a central maximum look like?
Student 8: Ok, when the light goes through the slit, there’s a, a broad band right and
then, ok I can’t remember if it is a double slit or single slit that does this,
but there’s, ah..the bands are evenly spread out towards either of the
sides of the central maximum.
Researcher: So the central maximum is a band of light, what colour is it?
Student 8: It’s black. No mam, white...ja it’s white.
Researcher: White …and um how broad is the band, compared to the other bands, are
they all the same size or what?
Student 8: Well with, Ok, there’s two, there’s a double slit and there’s a xxx uugh a
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single slit sorry, and it depends on which slit you use to direct the light, but
now I remember there was either one with a broader central maximum
than the other one, and then there was aah they were evenly spaced out,
in the double slit I think, the the xx was evenly spread out.
Researcher: Ok, what was the difference between the single and the double slit?
Student 8: Um, I think it’s the way the, the bands are spread out. ..Ah the one has the
… -
Researcher: The double slit, how does the double slit look like?
Student 8: I’m just going to say both; I’m not going to put a name to either. The one
the central maximum, from the central maximum the other bands are
spread out, I think (pause) I think it was a bigger spread than the other
one, I think so, and then (pause) mm now I can’t even remember, but then
all that I remember is that the spaces weren’t even in the one and in the
other the spaces were even.
Researcher: And you don’t remember in which one?
Student 8: MmMm, I think it’s the double slit.
Researcher: The double slit they are even spaced?
Student 8: Even spaces, ya.
Researcher: Do they both have that central maximum?
Student 8: Yes.
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Researcher: And all of this pattern is it all just black and white, or what does it look like?
Student 8: It’s black and white.
Researcher: Not red?
Student 8: (Pause) (Smile) (Maybe it’s red.)
Researcher: Did you see it?
Student 8: Yes I did see it.
Researcher: You did the experiment?
Student 8: Yes we did the experiment.
Researcher: Ok, um, then they asked: “If you had to do the experiment without the
laser, if you didn’t have the laser, you used a normal light bulb to do the
experiment would you see the diffraction pattern?” that you normally see
with a light bulb?
Student 8: I don’t think so.
Researcher: Why do you say so?
Student 8: Because the light in a light bulb isn’t as strong as a laser, because a laser
shines directly, the light bulb just … the light bulb just … it’s just a general
light, and then the laser shines directly through.
Researcher: Do you know what the word for that is, for shining directly?
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Student 8: Umm, …,no. (laugh)
Researcher: It’s coherent.
Student 8: Ok, (smile)
Researcher: Ok, last question, umm it’s this one. The question with the two car’s that
bump into one another and they said: “During a, in certain collisions
momentum isn’t conserved, when is linear momentum not conserved?”
You (L8) wrote: “The linear momentum isn’t conserved when both cars
move forward after the collision and the one car moves even further
forward.” Explain why you think momentum isn’t conserved when that
happens?
Student 8: (Pause)
Researcher: Why is momentum not conserved when they both move forward and the
one moves even more forward?
Student 8: Isn’t ah conservation of momentum when a car after collision stops, isn’t
that xxx that’s what I understand, like both the cars, like if the one car is
coming and …
Researcher: The one was just standing still and the other one was coming from the
back.
Student 8: So I would, did I write that the second car …
Researcher: Ok, you just wrote, um, let’s just find it exactly here (researcher looks at
the learner’s worksheet answer) you wrote: “It may not be valid that linear
momentum is conserved because both cars move forward after the
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collision, and car A moves even further forward, meaning that the
momentum is not conserved and the circuit does non conservative forces
such as force.”
Student 8: Ok, ah, (pause) (What was?)
Researcher: Why do you think that if they both go forward after the collision,
momentum is conserved?
Student 8: Because ah, I understood from conserve aah conservation of momentum
was that the car after the collision stops, ug… wherever it lands up it just
stops, and that’s what I thought.
Researcher: Ok, um, you said here that um “in a circuit there may be non conservative
forces such as force", tell me more about these forces that would hinder,
you are saying that they are non-conservative forces that are going to
hinder the conservation of momentum, what are these forces that would
stop the conservation of momentum?
Student 8: Aah, did I say force here?
Researcher: Ja, you said the circuit has non-conservative forces such as force.
Student 8: Ok, …last term I think we learnt about non-conservative forces, but I think
I got this section mixed up with another section, so I think the force the
non-conservative forces, I learnt about another one and then I mixed them
up and then I just was confused mam, ya.
Researcher: Ok, so you are not sure.
Student 8: Ja, I am not sure.
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Researcher: Ok, are there any questions that you want to ask me?
Student 8: (Shakes head no)
Researcher: Ok, I am going to give your paper back to your teacher, I will give her a
photo-copy of that, and there is just one thing that I want to explain to you,
because I didn’t tell you anywhere where you were right or wrong or
anything and I am not going to, except this one thing I am very tempted to
tell you, because you said you got the idea that momentum is conserved
when they stopped afterward, in this situation you had the one car that
was standing still and you had the other car that was moving forward so
before the collision there was momentum in the forward direction because
of the one car that was going forward, so if momentum is conserved,
which means it stays the same, then it means that you must have some
type of momentum afterwards, because the one car was moving forward,
so there was momentum forward so that means afterwards there must be
momentum forward, and for it to be conserved it must be the exact
amount, so that’s why there must be some kind of movement afterwards
because ...if they stop during the collision then it wouldn’t be conservation
of momentum, because you had momentum before that means you must
have momentum afterwards. When they stop it means, if they stop after
the collision then it means that the momentum before the time had to be
zero, now how would that have happened, they wouldn’t have collided into
one another if they were standing still, the only way that their momentum
before the time could have been zero is if they were moving in the
opposite direction because then their momentums are in opposite
directions, and they cancel one another out in a head-on collision, and hey
they have to have the same momentum before, or them to cancel out
exactly and to stop. Sometimes you have head-on collisions and they
don’t stop, but that doesn’t mean that momentum wasn’t conserved, it just
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means that if they go that way then that one will have more momentum,
not necessarily faster, more momentum can be faster or heavier, -
Student 8: Ooh,
Researcher: because momentum depends on mass and the velocity.
Student 8: Ooh, ok. Thank you mam.
N9: Interview with the ninth student on 14/08/2009 at 11h15-11h30
Researcher: There it is (referring to the learners’ worksheet) the one that you signed.
Student 9: Ja
Researcher: Umm
Student 9: That’s me.
Researcher: This is you. Ok, let’s find where you wrote that, ok I’m not going to show
you your marks now; otherwise you are just going to be worried.
Student 9: No, I won’t be worried, (aagh who cares.)
Researcher: It’s just the explanation questions and most kids do worse in the
explanation questions. Ok, so that is why I am doing the explanation
questions. Umm, actually it’s weird you do better in the sums-
Student 9: Mmm
Researcher: -than in the explanation questions.
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Student 9: That’s because it’s straight forward, you know the formula and you just do
it.
Researcher: Ok, right the question says: “When a laser emits red light and passes
through a single slit, then you get a diffraction pattern-
Student 9: Jaa
Researcher: -what does a diffraction pattern look like?” Ok you wrote umm, now I am
looking at the wrong question-
Student 9: Jaa I remember answering that.
Researcher: (pause as researcher looks for the learners’ answer for the question from
the worksheet)
Student 9: Did you type out all our answers as well?
Researcher: I haven’t yet; I’ve still got to do that.
Student 9: Aah whew, it’s a big project.
Researcher: Ok, there’s the circuit (pointing to the circuit on the worksheet) and they
said: “If that resistor burns out, what will happen to that voltmeter
reading?” Ok, you wrote: “If that resistor burns out, the voltmeter reading
will increase-"
Student 9: Jaa
Researcher: -which is right, " because there will be less resistance in the circuit.”
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Student 9: Yes.
Researcher: So first tell me if that one burns out, why will there be less resistance in
the circuit?
Student 9: Because there’s one less resistor (smile).Ok (laugh).
Researcher: That sounds pretty obvious. Ok, if there’s one less resistor so the whole
resistance has dropped, why is that going to make the voltmeter reading
go up?
Student 9: Because, if there’s less resistance then obviously there’s more power that
goes through the (stream) instead of if there were two resistors then,
obviously it uses more of the volts so if you can say, I don’t remember all
of this work anymore (Laugh), but I kind of figured, you know, if there’s
more resistance then the voltmeter reading would be less, because the
stream has to do more work when it moves,..or the power..electricity has
to be xx
Researcher: Ok, what does a voltmeter read, what does it actually measure?
Student 9: I know the Afrikaans word.
Researcher: Ok, tell me.
Student 9: Stroomsterkte.
Researcher: It measures stroomsterkte, the voltmeter?
Student 9: Ja.
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Researcher: Ok, so stroomsterkte in volts?
Student 9: Ja.
Researcher: Ok-
Student 9: AAH, that’s the ammeter!
Researcher: Mm, ok, so what does the voltmeter read?
Student 9: Potential difference or something.
Researcher: Ok, potential difference, what is potential difference?
Student 9: I have no idea anymore. (Laugh)
Researcher: Not sure at all what it is?
Student 9: AAH, it’s something to do with the batteries or ..I don’t know um,…
Researcher: Not sure what the potential difference is?
Student 9: No.
Researcher: Because the voltmeter reading does go up, but it’s not because…
Student 9: Why does it go up then?
Researcher: I will tell you now now.
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Student 9: Ok.
Researcher: Let me see where there was another question that I wanted to ask you. I
think that what it, ok, let me just check your other questions because I will
come back to that one now. The other question was, these multi-plugs that
you get, (pointing to a multi-plug) they have got cut-off switches, those
little cut-off switches over there (pointing to the cut-off switch on the multi-
plug).
Student 9: I didn’t have an idea what a cut-off switch is.
Researcher: Here it is (pointing to the cut-off switch on the multi-plug) you can push
that thing then it cuts off.
Student 9: So there’s no electrical flow.
Researcher: Yes, and they said: "why is it so important?", so you wrote: “It enables us
to stop the circuit from flowing through that plug and it cuts-off the circuit."
(Learner starts laughing quietly).
Researcher: Why is it so funny? (Smile)
Student 9: (Smile).
Researcher: Why do you think the cut-off switch NEEDS to cut off the circuit in the first
place?
Student 9: If there’s a overload of plugs or … in the plug…
Researcher: Overload of plugs, what is an overload of plugs?
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Student 9: Well, too many plugs using too much energy, electricity.
Researcher: Ok, and what happens then?
Student 9: Then something can blow a fuse, you know and (pause)
Researcher: Ok, why would they use more electricity, what would they use more of …
when you put too many plugs in there?
Student 9: (Pause) Well I think..I don’t know … maybe if you use different.. machines
or things that use a lot of power, and so it has happened before in our
house that the plug just wanted to blow up, because it was too much
friction or.. I don’t know? Power.
Researcher: What do you mean by power?
Student 9: Electricity. (Smile)
Researcher: Electricity. What do you mean by electricity? (Smile)
Student 9: The flow of electrons (smile)?
Researcher: So the flow of electrons becomes more?
Student 9: Yes, it becomes too much.
Researcher: It becomes too much.
Student 9: Mm.
Researcher: How are they connected, would you say, it that series or parallel?
314
Student 9: (Pause). I think it is series.
Researcher: Why?
Student 9: (Pause). I don’t know (Laughing) because they are in line there?
Researcher: Because they are in line?
Student 9: Ja.
Researcher: And that’s all I want to ask you, so let me go back and (researcher
switches off the tape-recorder and continues to explain the question the
learner asked previously, the one that the researcher said they would
come back to after the interview.)
N10: Interview with the tenth student on 17/08/2009 at 11h00-11h15
Researcher: I’m just going to ask you about three of the questions that you answered.
The first question that I am going to ask you about is the question about
the hydro-electric power station ... and uh in the hydro-electric power
station they say: “The water runs down and then about 85% of the waters
kinetic energy gets transformed into electricity, so what happens to the
other 15% that doesn’t get transformed into electricity?” So you wrote that:
“the other 15% is lost through other things such as heat, movement,
sound, etc.” Explain to me more about what you mean when you say the
energy is “lost”.
Student 10: When I say the energy is lost, I mean ... uh through when it was
transferred from the … what do you call it, xxx, yes, it was lost through,
they go through pipes right? Ja, and when they went through the pipes not
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the exact amount that was, the initial amount was not the one found at the
end, and the reason I came up with the fact, it could evaporate, it could be
lost through heat, vibrations, it could be lost through a lot of things, that’s
why I said etcetera, that’s what I understood by it.
Researcher: Ok, where would you say you got the idea from that energy is lost?
Student 10: Energy is lost, when we did xx, and let me think, when we did reactions,
that’s Chemistry, so I thought, ok, that happens when they ask you :”
where did the rest of the energy go?” and then you say electrons are lost
or they are gained, so I just took it from that..
Researcher: Umm … does this idea of lost energy match up with the law of
conservation of energy?
Student 10: (Pause.)
Researcher: Are you familiar with the law of conservation of energy?
Student 10: Yes. Energy not being destroyed or... ?
Researcher: Yes.
Student 10: But it can be transferred, yes it can be transferred, it does match up.
Researcher: And lost?
Student 10: Lost? No it doesn’t quite match up with it, lost, but the whole transferred to
from something else to another, like the initial amount to where it is lost
through heat…
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Researcher: Ok...ok let me find another one that you answered-
Student 10: It was probably transferred, ja, it can’t be lost.
Researcher: So you say it is transferred not lost?
Student 10: Yes it is transferred. It’s transferred not lost.
Researcher: (Cough) Ok, then this question, you have the two parallel plates um and
they say:” this is the way that a printer works” and basically the ink droplet
comes in, and the ink droplet has been negatively charged, and when it
comes between the parallel plates, it gets attracted upwards, so “what is
the charge on this bottom plate?”, so the ink droplet is negative, what is
the charge on plate B? You said um that: “Plate B is positively charged,
due to the fact that the negative and positively charged ink droplet will
work together to produce ink on the paper.”
Student 10: (Laugh)
Researcher: Tell me more about how this works. (Smile)
Student 10: Mam, that was much of a guess ... I seriously and honestly didn’t put any
applications into this question, I just … it was more of what I was thinking
...yes I I seriously, even now don’t understand why… that is so…
Researcher: Ok, so you’re not, you don’t know why you’re thinking that it’s positive,
why have you got the feeling that B is positive?
Student 10: That B is positive?...um I I have a … that if it’s negatively, uugh I have a, I
just guessed that if it’s negative then the plate at the bottom will be
positive, cause I just assumed that this line that’s the separation, I just
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took, like oh that’s positive and that’s negative, it was more of a guess, it
didn’t have any applications that we did, it was more of a guess.
Researcher: Ok, What do you know about how opposite charges react, if this was a
positive plate like you said, and that’s a negative, what do positive and
negative normally do, positive and negative charges?
Student 10: Usually uh they work together to produce whatever, and then negatively
and negatively, it’s the whole repelling and attracting.
Researcher: Ok, so would you say opposite charges attract or repel?
Student 10: They attract.
Researcher: They attract?
Student 10: Yes.
Researcher: So if this one was positive and the charge was negative, which way would
the droplet move?
Student 10: It would move this way?
Researcher: Which way, up or down?
Student 10: Down.
Researcher: And it hasn’t done that hey?
Student 10: Yes.
.
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Researcher: So what does that mean do you think?
Student 10: (Smile). It divides up.
Researcher: Why do you think it divides up, instead if they are attracting one another?
Student 10: Uuh, that means that it doesn’t necessarily work the way that charges, I
think that charges work.
Researcher: If B was negative and the ink droplet was negative then what would they
do, what would the two negatives do?
Student 10: They would repel and it think it wouldn’t, it would go straight or it wouldn’t
work at all I think.
Researcher: If they repel, which way would the ink droplet move?
Student 10: Umm, I will take a wild guess, I think it will go straight or go the other way.
Researcher: Ok, ok… last question. This one was about the light meter, a camera has
got a light meter in, to measure the intensity of the light, and the way it
works is that, you shine the light on it and then there’s a metal object that
releases electrons and creates a current, which makes the meter give you
a reading. Umm (cough) in the question they asked: “What happens if they
increase the intensity of light, without changing the wavelength of the light,
they just increase the intensity of the light, what happens to the energy of
the electrons that are emitted?” -
Student 10: If they increase the?
Researcher: If they increase the radiation, in other words the amount of light.
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Student 10: But they don’t increase the?
Researcher: They don’t change the wavelength, they just increase the radiation. What
is going to happen to the energy that the little photo-electrons have got
that are emitted.
Student 10: Isn’t it going to be more?
Researcher: Ok, you said, I think that is what you said, you said: “The energy of the
emitted photo-electrons will increase and then return to its original energy
level and will have a new born or gain electron during the energy transfer
of energy.” So explain to me why do you think that when they increase the
radiation the energy of the photo-electrons increases?
Student 10: Well I, I uh, remember the whole photo-electron when they say um,
something about when you increase … I think the energy or something,
and then another one is xx created on the way, I can only draw that, I am
more practical, I can draw that and explain like that, just like you increase
the radiation but the wavelength is the same, but it’s going to change the
photo-electrons, there is going to be more, that’s what I understand, I think
I can explain on paper.
Researcher: Ok, do you want to explain on paper?
Student 10: Remember the whole. (Learner starts drawing a diagram on the
worksheet)
Researcher: Is it working? (Referring to the pen)
Student 10: Yes it’s working. There was the whole (continues drawing) I can’t
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remember exactly, it looked like a capsule I think, and there was
something about, I think when energy increased? Or something, along the
way a new electron is, is born, and then they increase so that’s why I said,
ok I can’t remember, can’t really explain it, can’t really explain why…
Researcher: What do you mean by: “a new electron is born?”
Student 10: (Pause) There was this other one that I read, before I read this because
xxx photo-electrons, and I remember it saying something when you
increase the energy or something like that a new electron is formed, that’s
what I understood by it, that’s why I say it will increase, does it increase
the radiation?
Researcher: Ok, ok ...that’s all … have you seen a photo-electric cell or a light- meter?
Student 10: Yes but only on paper.
Researcher: Only on paper?
Student 10: Yes.
Researcher: Ok, so in your textbook basically or a picture somewhere?
Student 10: Yes a picture.
Researcher: Ok, that’s all, are there any questions that you want to ask me?
Student 10: Yes I want to ask you mam, um Science this year it’s tough, (smile)so
mam I was just since while you are interested, well I think you want to
help, yes, since well you’re going to help , I am suggesting that we should
go, you know going through papers it’s more like these days you just get
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the same questions and then, you like, kind of like store it in your head, we
don’t really sometimes understand what’s happening and what… what’s
going on we just store it, and oh I remember reading something about this
so I’m just going to say this, and its more about that, and it’s really bad so
that’s why I, cause I really understand xxx
Researcher: So you mean going through a lot of exam papers gets boring?
Student 10: It does.
Researcher: And then you don’t really understand it anyway?
Student 10: I only understand the chemistry this year, it’s nice, but the Physics part…
and it’s not only me (my friends …) I didn’t understand this… well.
Researcher: Ok… ok thank you. (The researcher then put the tape-recorder off and
attempted to give the learner advice, without interfering. The researcher
also informed the learner that her teacher would be returning their
worksheets with an extended memo to them.)
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Appendix O
Transcripts of teacher interviews
O1: Interview with the first teacher – the Head of the Department – on 14/08/2009
at 9h15-9h45
Researcher: Right, there are no right and wrong answers it’s just your opinions.
Teacher 1: Oh, ok.
Researcher: Ok, so the first question is: tell me in your experience with the learners in
your class, how common are learner’ misconceptions?
Teacher 1: (Pause) Very common, I think um especially in the earlier grades, if I take
in my case with Life Sciences, if you take the grade 10 learners and you
have to work towards matric and you are teaching them different things,
like the grades 10’s you still battle because they really, the level of
understanding and the language ability is very poor at times, but then if
you work with them by the time they are in matric I am quite happy with
them, yah..
Researcher: Ok, How do you think learners develop misconceptions?
Teacher 1: (Pause) whew I still think that um there is a language thing involved
because they, they just do not sometimes understand what you are
explaining to them, because it’s not in their world, um, they don’t know,
you know we take it that they all have experience and that they all read
and that they all have general knowledge, and these days they have very
little general knowledge, and they’re also not interested to read or to look
at programs that will develop them, nothing like that, so I think
misconceptions, but maybe also if you do not teach properly, I have found
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that sometimes you will just explain something very quickly and then do an
exercise on it and the answers that you get tells you gosh they didn’t
understand a word you said, so you have to re-teach that, um, with time I
have seen that many teachers do that, I do go back and do it (smile). I
think it is a very, with both, but to me the learners, uugh, the interest level
is very low at times.
Researcher: From your point of view what would you say are the main sources of
learner’ misconceptions?
Teacher 1: (Pause) Umph Gosh you give me difficult ones (smile)
Researcher: (Laugh)
Teacher 1: Main sources of learner’ misconceptions. (Pause) I would say um
…improper maybe preparation beforehand that you just fire away that you
teach them something that you did not really prepare the basic concepts
enough, In Science very often they come and they have no basic
concepts…and you fire away like with electricity in a certain and you just
do that, they have no idea really, you know they still think that it comes
from a pole, ...so um I would say teacher preparation before hand to really
find out what they know…and to prepare them ..ah to go back I think that
is one of your big things …um …um…ja… and then ja ..I can’t think of
anything else now ... xx sources, and of course the reading, ooh the
reading level that is a big problem with some of our learners they, they just
cannot read and they also cannot hear. You can explain something very
basically to them and you ask them: "repeat what I’ve just said to you" and
there’s just no ability to take in what you’ve said ...uuh... (Background may
be a big problem)…
Researcher: Um. How would you define a misconception?
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Teacher 1: A misconception. (Pause) Ah to me a misconception … not understanding
what exactly um a specific thing implies …or misunderstanding, having a
complete different picture of a certain concept, …, because I have often
found you know, you know what the concept is you know what the
definition is, but sometimes the interpretation is so different to yours and
they actually teach you about it and it is like wow I never thought you
could look at it that way. So a misconception I just think it is changing the
complete idea of what something is, or not understanding it completely.
(Pause)
Researcher: Ok, um. What strategies do you use or have you tried which may remedy
learner misconceptions?
Teacher 1: (Pause) Well everything. Uuh…ok…I’m still dreaming of my projector to
come in, because I’m sure if you can show them certain of these things it
will help a lot. I have tried everything, if I have a child that does not
understand, firstly you have the class where you teach, where you explain,
still no understanding I sit one to one with that child, I really do make time
to do that, even whilst they are busy with work in class I will sit with that
child and see if I can get them, still nothing then I will go home and think
about it and start with other sources, pictures..um practical things where I
take them to the practical you know show them, it links with this and this
and this, try and get them, no grasp yet, I’ve had it now with evolution with
some of the things, then I print out a lot of transparencies, because I still
don’t have my projector going, and then I show them this is where it starts
this is how it works and then hopefully from there we will have some of it
going (smile). But um you know with the resources available you try and
do and do as much as possible. I’ve got piles and piles of National
Geographic’s which I actually page through and show them pictures, I
really try and do a lot (Laugh softly).
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Researcher: Ok. Have you received any training or attended any course or meeting
where learner misconceptions um or strategies to remedy them have been
discussed?
Teacher 1: Umm, no not since I’ve been teaching. Um I have attended years
ago...separate courses on brain development …um…xxx a lot of those
types of things, I was very young then, but I attended and those are
helping me now I wouldn’t say specifically my teacher training or anything
for that matter, and then I also studied up to Honours in
Psychology…which helps me to understand the children and to
understand, to see in their eyes when they do not understand, to see in
the body language when they do not understand, and I do believe
unfortunately we do not have enough time, I do believe that the naughtier
they are and the more they move about, the less they just do not
understand what you are teaching them, so sometimes I will stop a class
and I will say, you don’t understand the work do you?, then they say no
we don’t, then I say let’s see if we can make a plan and show it to you in a
different way, but I think very often teachers just think they are very
naughty and you know that type of thing, so I would say that my
Psychology training, the fact that I was involved with ..um...a mother who
was ...wat is dit... a counsellor herself, advantaged me, and as far as
training goes with regard to misconceptions, no nothing.
Researcher: Ok, and at subject meetings do you ever get to discuss it there?
Teacher 1: No, at subject meetings we moderate and run away (Laugh)
Researcher: (Laugh) Ok, um. Have you come across any articles on learner’
misconceptions while reading?
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Teacher 1: Yes, I will say if you, if you are the type of person that will specifically go
into that, like ah …there’s very often articles in newspapers like the frontal
develop you know that frontal lobe of teenagers that is not fully developed
yet, their behaviour in class and everywhere in general, towards it, that is
if you are interested to read on that. Yes there is articles in magazines,
there are programmes on DSTV and the internet. If I sometimes have a
child, I will go and read on it, like a child will tell me: “My mother said I
suffer from this.” Then I will actually go and look it up and see how it
affects the child, I doubt if many others do it .…
Researcher: Ok-
Teacher 1: But it’s my interest. I like it. (Smile)
Researcher: Ok, um. In your opinion would practical work and experiments HAVE any
effect on learners’ misconceptions?
Teacher 1: Yes it would, if you had enough time…and enough resources um very
difficult if you work with a class of 35 um…and above …to actually really
ah always do these practical’s because they do get very excited, but I do
believe yes I’ve seen that ..they ah.. you have learners that have such a
poor knowledge on the stuff and if you do a practical …it does help them,
the practical today didn’t help (laugh) but then you should explain very
thoroughly why it didn’t work, but I have seen they ABSOLUTELY LOVE
PRACTICALS and in Technology, ooh they enjoy that, it’s just extremely
noisy, like the problem I had last year is whenever we would hammer
away, because we did not have a specific class for Technology, they run
upstairs from the classes downstairs and they say: “ you are making a
heck of a noise, can you stop!” so there’s a lot of complaints from teachers
around you, when you are busy with practical xx (Laugh) which is a big
problem, if I can have a class in the corner I will just hammer away, so that
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is limiting, but they LOVE to do practical’s, they really do and they
understand the work better and they’re more LESS disruptive.
Researcher: Umm, in this one question that the children did for me, it was a practical,
and the majority of, and they didn’t, and the majority of the kids got the
question right because they had to describe what they SAW, so if they
hadn’t seen it, ok they could have seen it in their textbook but they most
probably wouldn’t remember, but I guessed from the fact that so many
kids got it right that they had seen it, but there were some children that got
it wrong and when I asked them if they had seen it, you know, they said:
“yes, they did the experiment, this was what the experiment was like but
they can’t remember what it looked like.” Why do you think that
sometimes, why do you think it is that sometimes you do the experiment,
the kids do it, they remember doing it, but they can’t remember what they
saw or what the results were or what they were meant to learn, so in fact
sometimes it doesn’t actually help, why do you think that happens
sometimes?
Teacher 1: You know I’ve even done some of those myself um, were... if I think back
when I ... now I’m going to take it to my own…maybe that will help, when I
studied ah..further I didn’t have Science for matric so when I entered the
class like for the third week they did acid and base titrations …now if you
have never seen or you don’t really know what acid and bases is and that
type of thing …they taught us in class and everything was there but when
they did the practical to me it was so foreign …that I was just so
completely lost, and I stood there and I eventually asked the lecturer:
“what exactly are we doing?”, he gave me a terrible answer of: “You
should leave Science, because you will never amount to much”, and up to
this day I remember the class, I remember we did it, but I remember
absolutely NOTHING of what we did. Umm I do think you should have
some knowledge if you do a practical, because otherwise you just, and
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sometimes a learner just ...isn’t there yet, you do, because you now, ok
you say we are going to do this practical today and half the class or three
quarters don’t fully understand exactly what you are doing and you are
explaining to them time and time again, but I must admit there are some
learners that even after you have shown them so many times, they’re still
just not there, they do not understand why you are doing what you’re
doing. I don’t know?
Researcher: Ja, I know it is difficult. Do you think that language would have any effect
on learner misconceptions?
Teacher 1: Yes I do believe that very, yes I do, absolutely...because I have seen in
the past that with learners, I’ve had learners that came in like in grade 8
from schools, rural schools, where they, their English is so limited …and
it’s so difficult to get them to understand what you are doing, no language
definitely…
Researcher: Ok, and the language of Science terminology does that have an effect?
Teacher 1: Yes, yes and your ability to understand that language, ah, and if you are
good with language, if I take Life sciences, if you have a strong language
ability it’s easy to remember all those Latin ... words, and to you know... if
you do not have that ability you can eventually be in matric and you still
battle to spell it and to write it... very specific to children…
Researcher: Ok that all the questions that I have for you. Do you have any questions
for me? (Smile)
Teacher 1: No, I understand why you ask me all these questions, very difficult to put it
into words though, but thank you very nice to once again think, you should
always think on what you are doing.
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O2: Interview with the second teacher – the grade 12 teacher – on 17/08/2009 at
8h30-9h10
Researcher: Question number 1, ok, there are no right or wrong answers obviously, it’s
just your opinion ok, so tell me in your experience with the Science
learners in your class, how common are learner’ misconceptions?
Teacher 2: I think quite common, and it seems to be increasing every year more and
more ja.
Researcher: Ok, why would you say it’s increasing, what do you think it is?
Teacher 2: If I compare my first matric group this is now my second, I think of the
grade 11’s now that are going to matric next year, um, I have to explain
something to the grade 11’s three times, where my first group three years
ago I had to explain it once and they immediately understood. (Pause.)
Researcher: Ok, …, ok, how do you think learners actually develop misconceptions?
Teacher 2: I think it comes from lower grades where they don’t um, they don’t learn
the correct words and what is expected when we say, explain versus
define versus um, state, things like that. I think that is the main issue, they
don’t, they read but they don’t understand what they are reading. Not
necessarily they don’t understand the work, they just don’t know what I
want them to say.
Researcher: Ok, from your point of view what would you say are the main causes of
learner misconceptions?
Teacher 2: (Pause.) The main sources I would think, reading problems, difficulty in
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reading and understanding, I would say that is the main problem and
then... then secondly I would think mathematical literacy, to be able to
understand Maths, that’s the second thing, so after they have understood
the question, they don’t know how to do the Maths. (I think those are the
main ones.)
Researcher: Um, how would you define a misconception?
Teacher 2: (Pause.) To… to read a question and not to understand it properly and
therefore your answer is incorrect versus the question, it is not necessarily
scientifically incorrect but it is not related to what the question actually
asks.
Researcher: Ok… um what strategies do you use or have you tried, which may remedy
learner’ misconceptions?
Teacher 2: I always try to explain one concept at least in three different ways, and
then I also have, every week at least one extra class, where kids that feel
that they still don’t understand it can come back to me, and then I can
have a one on one talk with them, and I try also to put it in their own words
and in their context of what they understand, cell phones and what they
like, Mix-it and things like that..um and that’s the one way … I try to make
it funny, they remember if you put some humour into it, they remember it
better.
Researcher: Ok… um have you receive any training, or attended any courses or
meetings where learner misconceptions, or strategies for remediating
them, have been discussed?
Teacher 2: No… I have been to courses where the work has been discussed and how
you can do a practical or so, but never misconceptions.
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Researcher: So at your subject meetings it never really comes up?
Teacher 2: No.
Researcher: And have you marked matric papers?
Teacher 2: Um no I hope this year will be my first.
Researcher: Ok… um … Have you come across any articles on learner’
misconceptions, while reading about Science?
Teacher 2: Also no. (Pause) I know it is a discussed topic in the school at the
moment, that’s why they have this grade 8 program … um where all the
grade 8’s have a little, every register period they write a little, do an activity
or write a little test … to help them to learn certain words, because like it’s
not only a problem in Science, I think it is a overall problem for everybody,
everybody struggles with it, and that’s why they have, they have started
the program this year, from grade 8 to just up their level of language use
and understanding.
Researcher: Which subject do they do it in?
Teacher 2: In the register class, so it’s not a particular subject. In register class they
get a little exercise or a test, but it’s not related to a specific subject.
Broad…
Researcher: Ok… is it a school project
Teacher 2: Yes… they started at the beginning of this year and I hope that we will
have the results at the end of the year, to see whether it helped at all.
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Because many, many many, teachers complained that they found that
problem, specifically, so that’s why they started this program … and they
have to define certain words and explain, just to try and teach them what
is expected of them when a certain question is asked in a certain way.
Researcher: Ok. … Have you come across any misconceptions in Science textbooks?
Teacher 2: (Pause). Mm ... not that I can put my finger on, but I’m sure that there
would be, there would be I’m sure.
Researcher: Ok. … Um, what are the most common misconceptions that you have
come across in your grade 12 learners’ Physics papers, ones that come
up a lot?
Teacher 2: (Pause). The grade 12’s, let me just look at the topics (looks at textbook).
Um, oh the Physics.
Researcher: Ja.
Teacher 2: (Pause). I know they struggle with force and work and power um ..
electricity a little bit, especially because we only do electromagnetism and
they forget what they have learnt in grade 11 with the circuits and the thing
like that um, they don’t struggle with projectile motion that, they find that
quite easy … what else have we done ..um electromagnetism I would say
is a big one (pause).
Researcher: How do they do with energy?
Teacher 2: Ja that’s the work and power, momentum is ok, they are fine with
momentum and impulse, that they are alright with um but with energy,
work, power they struggle and electromagnetism.
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Researcher: Ok… um in your opinion would practical work and experiments have any
effect on learner’ misconceptions?
Teacher 2: I think it would, they LOVE doing practical’s, they always want some type
of explosion though, they love doing practical’s, and then they also SEE it,
we don’t only talk about it, they SEE it, and I think the kids are visually
stimulated, they look at things over the TV and they’re visually stimulated,
so seeing it helps, I think it would have a HUGE impact.
Researcher: Sometimes we do experiment, and when we ask them questions later it’s
like as if they have never seen it, why do you think that sometimes it
doesn’t actually work?
Teacher 2: Because I think that um due to the big class ... and expensive equipment,
you can’t always let everybody do his own experiment and so it seems as
if the group is doing well... but I think it’s the clever kids or the kids that
understand more that do most of the work and then you have spectators
which only looks, who doesn’t participate, I think that’s the biggest
problem, if it were possible that everybody does their own experiment it
would be very easy to identify who actually understands what they are
doing and who does not. I think with group work the higher academic
performers, if you can say so, they want to do good, they kind of take over
as leaders,.. and the weaker pupils just look … what they are doing, so
you don’t know if they understand it or not, if you ask them they say: “Yes”
…
Researcher: Ok … do you think language has any effect on learner’ misconceptions?
Teacher 2: (Pause).
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Researcher: How do you find, what problems do your second language learners have?
Teacher 2: Well at this school all of them, it’s their second or even third language, um
and I really think the English, the English learners understand the words
better, and in Science you get, it’s not the normal English words, (we) talk
about Coulomb and... induction and all these fancy words, so to
understand that on top of maybe a language issue, where they only speak
English at school, but with their friends or at home another language, yes,
they definitely do have a disadvantage.
Researcher: Ok, and do you think that the Science terminology that you spoke about
now, how does that affect learner’ misconceptions, amongst all the
learners?
Teacher 2: After a while if you repeat it many times they get used to it, but … it is
necessary to repeat over and over, the units, the words, etc. I think in
grade 8 and 9, um there’s really not enough emphasis on using the correct
words, and even grade 10 I’m starting to get them used to the words, so
that when they get to grade 11 suddenly they are bombarded with all
these, these words, and they get confused. I think that maybe if we
start using it in grade 8 and 9 and 10 more often, it would help them when
they get to grade 11 and 12, but generally they cope.
Researcher: Ok…
Teacher 2: It is just necessary to repeat it and help them study it.
Researcher: Ok, ok, thank you that’s all, are there any questions that you wanted to
ask?
Teacher 2: Umm…
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Researcher: No questions?
Teacher 2: I would just be interested to find out (how the learners did.)
Researcher: (The researcher then switched off the tape-recorder and then gave the
grade 12 teacher copies of the student’s marked worksheets as well as
sufficient extended memorandums for herself and her students.)