what is conceptual learning in chemistry and why should we promote it?

CMU 2009 http://www.chemcollective.org 1

What is conceptual learning in chemistryand why should we promote it?

David Yaron+, Michael Karabinos+, Jodi Davenport*, Jordi Cuadros+

Department of Chemistry+ and Psychology*, Carnegie Mellon University Gaea Leinhardt, Jim Greeno, Karen Evans

Learning Research and Development Center, University of PittsburghLaura Bartolo+, John Portman*

Department of Information Science+ and Biology*, Kent State UniversityW. Craig Carter, and Donald Sadoway

Department of Materials Science, MIT


NSDL

ChemDLMatDL

Digital Library and Projects Overview

Chem Ed DL

Portal for all of chemistry

Collaboration between ACS and J. Chem. Ed.

www.chemeddl.org

Materials for Introductory chemistry Virtual labs Scenario based learning Tutorials

Can a digital library provide a community space for promoting conceptual learning in chemistry?

www.chemcollective.org

ChemCollective

Open Learning InitiativeOLI

Pittsburgh Scienceof Learning Center

PSLC

OLI

Full online courses

www.cmu.edu/oli

PSLC

Fundamental studies to advance the theory of learning

www.learnlab.org


ChemCollective as a Digital Library

ChemCollective

LearningTechnologist Educators

LearningScientists

Configurable virtual lab

Tools for creating explanations and assessments

Tools for data collection

Activity and curriculum creation

Feedback on classroom use

Domain analysis

Learning assessment


What is conceptual learning?

• Physics’ Force Concept Inventory– Mathematical problem solving does not necessarily lead to ability

to answer qualitative questions– Students learn what they practice.

• Physics’ answer to “What is conceptual learning?” – Non-conceptual instruction

students struggle with hard problems

– Conceptual instructionCouple mathematical problem solving with qualitative questions


Conceptual learning

• Being systematic about the goals of instruction and aligning the instruction to these goals

• Four projects related to conceptual learning– Virtual lab– What is needed for scientific literacy?– Teaching chemical equilibrium– Molecular science across disciplines


Virtual laboratory

• Goal: Connecting mathematics to authentic chemistry

• Approach: Problem solving that involves experimental design and data analysis

• Virtual Lab: Ability to “see” inside a solution removes one level of indirection in chemical problem solving


Classroom uses

• In a computer lab • As take-home work• Pre- and post-labs • Lab make-ups• Supplement to in-class demonstrations

• Current topic list– Molarity - Stoichiometry – Quantitative analysis - Chemical equilibrium – Solubility - Thermochemistry – Acids and bases

• Problem types– Predict and check– Virtual experiment

• Labs designed to be similar to common physical labs• Puzzle problems (open-ended and inquiry based experiments)


Virtual lab use• Replacing textbook-style problems with experimental design and data analysis problems

• Breaks shallow “means-ends” problem solving strategy– 4 sections of 30-45 students working alone; 4-5 instructors/observers– The Virtual Lab format requires students to go beyond matching words to equations

Typical textbook problem“When 10ml of 1M A was mixed with 10ml of 1M B, the temperature went up by 10 degrees. What is the heat of the reaction between A and B?”

Virtual Lab problem“Construct an experiment to measure the heat of reaction between A and B?”


Virtual lab use

“The virtual lab contains 1M solutions of A, B, C, and D. Construct experiments to determine the reaction between these reagents”

100 mL 1 M A + 100 mL 1 M C 0.25 M A + 0.25 M B + 0.25 M D

• 50 % of students put A as reactant and productA + C A + B + D

• Actual reactionA + 2 C B + D


Virtual lab use


100 mL 1 M A + 100 mL 1 M C 0.25 M A + 0.25 M B + 0.25 M D

• Find stoichiometry through titration– Slowly add 1M A to 100 ml of C until all the C is consumed– 50 mL of A leads to 1:2 ratio of A to C in the reaction A + 2 C


Virtual lab use


Single step solution– Mix equal volumes of 1M A, 1M B, 1M C, and 1M A B C DInitial 0.25 0.25 0.25 0.25Change -0.125 +0.125 -0.25 +0.125Final 0.125 0.375 0 0.375 A + 2 C B + D


Assessment within a large lecture course

• Study at Carnegie Mellon– Second semester intro course, 150 students

• Information used– Pretest– 9 homework activities (virtual labs with templated feedback)– 3 hour exams– 2 pop exams (practice exam given 5 days before hour exam)– Final exam


Correlations

PreTest

Home-work Pop Exam Exam Final

Pretest

1.00

Home work 0.03 1.00

PopExam

0.50 0.15 1.00

Exam 0.32 0.43 0.51 1.00

Final 0.23 0.58 0.37 0.59 1.00


Regression and structural equation model

• Linear regression accounts for 48% of the variance in the final grades• Influence of homework accounts for half of the model predictions• Structural equation model supports conclusions drawn from the regression


Assessment within OLI online stoichiometry module

• Study design– Treatment (20): Online course

including a scenario, tutors and virtual lab homework

– Control (20): Paper and pencil, worked examples and practice

– Assessment was traditional problem solving of quantitative stoichiometry problems, and some qualitative questions

Text-onlyMean=65

MultimediaMean=77

Virtual Lab use was positively correlated with better performance.


Conceptual learning in chemistry: What is it?

• Virtual laboratory– Connecting mathematics to authentic chemistry

• What is needed for scientific literacy?• Teaching chemical equilibrium• Molecular science across disciplines




• What is needed for scientific literacy?• Teaching chemical equilibrium• Molecular science across disciplines


Traditional high school course structure

• CA state standards– Standard 1 Atomic and Molecular Structure – Standard 2 Chemical Bonds– Standard 3 Conservation of Matter and Stoichiometry– Standard 4 Gases and Their Properties– Standard 5 Acids and Bases– Standard 6 Solutions– Standard 7 Chemical Thermodynamics– Standard 8 Reaction Rates– Standard 9 Chemical Equilibrium– Standard 10 Organic Chemistry and Biochemistry– Standard 11 Nuclear Processes

• Current chemistry AP exam guides are similarly structured around chemistry topic list


Domain analysis for chemical literacy

• Evidence of the domain as practiced– Nobel prizes for past 50 years (1952-2002)– NY Times Science Times for 2002 (54 reports)– Scientific American News Bites for 2002 (32 reports)

• Evidence of the domain as taught– CA state content standards – Best selling textbooks


Domain map

EXPLAIN ANALYZE SYNTHESIZE

Hypothesis Generation

Hypothesis Testing

Goal(What do you

want to know?)

Process(How to determine

What you have)

Functional Motifs

StructuralMotifs

AssemblyMotifsTOOLBOX

RepresentationalSystems

QuantificationSystems


Full domain map

TOOLBOX

RepresentationalSystems

QuantificationSystems

Nomenclature Structure

Atomic Structure

VSEPR

MolecularStructure

Lewis DotOrbitals Configuration

Reactions

Format Stoichiometery

Units Mole Molarity Partial Pressure

SYNTHESIZE

ProcessMotifs

StructuralMotifs

CovalentBonding

Simple Organic

Transition MetalComplexes

(Metal Ligand)

PolymersBiological

Non CovalentBonding

SimpleMolecules

3-D NetworksMetals / Alloys /Semiconductors

Molecular Crystals

Non-Biological

Ionic / Alloys

Van der Waals /Electrostatic

UV/VisIR

NMRMassSpec

Titration

PaperTLCGas

ColumnHPLC

Chromatography

ANALYZE

Method(How to determine

what you have)

Investigation

Separation

Spectroscopy

Types ofReactions

Redox

Acid and Base

EXPLAIN

Radioactivity

ThermodynamicsHeat and Energy

Phases of MatterLiquid, Solid, Gas

What is a Metal,Crystal, Salt?

Properties ofGasses

Properties ofSolutions

Acids and Basesin Solution

Properties ofMatter

Equilibrium

Kinetics

HypothesisGeneration

(Frameworks an expertsifts through to construct

an explanation)

HypothesisTesting

StructureProperty

Relationships

Similar structureas an explanation

Radio Label

Selectively shutdown pathways

CorrelateObservables

Hold one thingfixed whilechanginganother

Scavenge O2

Block afunctional group

Is composed of Is composed of Is composed of

MicroscopyTechniques

ScatteringTechniques

Extraction

Distillation

Stoichiometery

Electro-magnetism

RadioactiveDating

Molecular StructureQualitativeAnalysis

(What is its Structure)

QuantitativeAnalysis

(How much do you have)

Goal(What do you

want to know?)

Super MolecularStructure

Atomic Structure NewElements

FunctionalMotifs

Catalysts

Materials

PharmaceuticalsFood and Health

Energy

ChemicalDesign

BiologicalEngineering

Filtration

Separation

PaperTLCGas

ColumnHPLC

Chromatography

Extraction

Distillation

Filtration

Precipitation

Formulation

Catalysis

Properties ofAtoms andMolecules

Periodicity

Evans, Karabinos, Leinhardt & Yaron, J. Chem. Ed. (2006)


Results of text analysis

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Synthesize

Analyze

Explain

Toolbox

Chem in TextbooksChem in the World


Scenarios: Examples

• Mixed reception (molecular weight, stoichiometry)• Cyanine dyes binding to DNA (equilibrium, Beer’s law)• Meals read-to-eat (thermochemistry)• Mission to mars (redox, thermochemistry)• Arsenic poisoning of wells in Bangladesh (stoichiometry,

titration, analytical spectroscopy)• Ozone destruction (kinetics)




• What is needed for scientific literacy?– Replacing skills focus with knowledge of what chemists do

• Teaching chemical equilibrium• Molecular science across disciplines





• Teaching chemical equilibrium• Molecular science across disciplines


Chemical equilibrium

• Goal: Discovery why this topic is so difficult to learn, and try to fix it

• Approach: – Domain analysis– Student talk alouds on traditional problems– Discovered “implicit knowledge” that could be made explicit in the

instruction


Chemical equilibrium

• Goal: Discovery why this topic is so difficult to learn, and try to fix it

• Approach: – Domain analysis

1. Utility of the knowledge2. Detailed structure of the knowledge3. Psychological aspects of the knowledge

– Student talk alouds on traditional problems– Discovered “implicit knowledge” that could be made explicit in the

instruction


Chemical equilibrium / Acid-base chemistry

1) Utility of the knowledge– How is this knowledge used in organic chemistry and molecular

biology1) Compare pH to pKa to determine ionization state

2) Buffers used to control pH (qualitative not quantitative)3) Titration as an analytical technique

– Current instruction1: Almost a footnote (in the pH indicators section)

2-3: Coverage may not be sufficiently qualitative


Chemical equilibrium / Acid-base chemistry

2) Detailed structure of the knowledge– Need to be flexible with “progress of reaction”– General strategy (majority/minority species strategy)

3) Psychological aspects of the knowledge– LeChatlier (especially with addition/removal of a species) is most

retained concept– Broad confusion regarding “progress of reaction”

• Q (current state) vs. K (state towards which system tends)• Meaning of “initial” vs. “equilibrium” state


What can we build on?

• LeChatlier’s principle plays role of “prior knowledge”• Human respiration is scenario to which to attach “initial” vs.

“equilibrium” state– Blood entering lungs and muscles experiences a new initial state– Blood leaving lungs and muscles has reached a new equilibrium

state


Progress of Reaction

• Based on expert/novice protocol study 2NO2 N2O4


Majority / Minority Problem Solving Strategy

• Old instruction– “Small x approximation”– Highly mathematical

• New instruction– Majority/minority species strategy– Couples the problem solving steps to qualitative reasoning


OldInstruction

Small x approximation


NewInstruction

Step 1:Push strong reactions to completion(identify majority species)

Step 2:Use K=Q to find [ ]’s of minority species


Results

• Coordination of core concepts with problem solving procedures led to large improvement in problem solving performance.


Majority vs. minority species

• A general strategy– Find all strong reactions (K>>1)

• Acid base: OH- + H+ ; HA + OH- and A- + H+

• Solubility: M+ + X- and M+ + L

– Thought experiment: Assume large K’s are infinite and do a limiting reagent calculation

• All species that do not go to zero, are majority species and you now know their concentration

– Determine minority species, via equilibrium expressions (K=Q)





• Teaching chemical equilibrium– Connecting problem solving procedures to chemical

concepts/mental models• Molecular science across disciplines






concepts/mental models• Molecular science across disciplines


Conceptual frameworks that cross disciplines

• Scope is molecular science– How molecular structure and motion lead to emergent macroscopic properties– The synthesis/engineering of structures with desirable properties

• Build materials for discipline-specific courses, but that use a common core set of materials to show interdisciplinary connections

• Experts from multiple domains (chemistry, materials science, biophysics) met to identify concepts/frameworks that are– Central to their domain– Have strong leverage– Are difficult to teach/learn


Outcome of the Design Process

• Reaction paths and energy landscapes

• Used to describe, for example,– Organic chemistry reactions– Diffusion on surfaces– Protein folding/unfolding


Development process

• Analyze content with experts, novices and psychologists• Sequential focus on aspects of the diagram

– What is Q?– What is temperature?– Energy vs. free energy


What is the reaction coordinate Q?


Motion connected to a heat bath


Coordination


Entropy: Energy vs. free energy


Other conceptual frameworks of molecular science

• Reaction paths and energy landscapes• Molecular forces

– e.g. Structure formation at different temperatures• Economies of exchange

– Heat, proton (acid/base) and electron (redox) exchange• How natural and designed systems promote one chemical

process over another– e.g. Kinetic vs. thermodynamic control






concepts/mental model• Molecular science across disciplines

– Conceptual frameworks that have broad utility


Digital library assessment

• Web logs

• Monitoring the pathway from seeing to contributing– Target audience: 9000 college and 100,000 high school instructors– See the collection: 7000– Use the collection: 200– Contribute to the collection: 62

• 11 have contributed activities (56 activities)• 11 have contributed translations (11 languages, 70 activities)• 40 have given feedback, 13 volunteered for learning studies

2004 2005 2006 2007 2008

ChemCollective Website Unique Visitors 101,397 106,429 123,400 161,481 211,477 Vlab (individual users) Access the applet to perform experiment online 18,757 48,626 59,733 62,871 117,875 Download the virtual lab to local drive 4,329 6,425 15,678 17,556 24,530


Closing comments

• Can digital libraries serve as community spaces for promoting conceptual teaching and learning of chemistry?– Virtual lab does get reused and repurposed

• Homework tool• Many instructors find the approach compelling

– Chemical equilibrium and cross-disciplinary materials• Too soon to tell

– Shifting high school chemistry from skills to literacy• No progress yet


Carnegie Mellon• Michael Karabinos• Jodi Davenport• Donovan Lange• D. Jeff Milton • Jordi Cuadros• Rea Freeland• Emma Rehm• William McCue• David H. Dennis• Tim Palucka • Jef Guarent• Amani Ahmed• Giancarlo Dozzi• Katie Chang

• Erin Fried• Jason Chalecki • Greg Hamlin• Brendt Thomas• Stephen Ulrich• Jason McKesson • Aaron Rockoff• Jon Sung• Jean Vettel• Rohith Ashok• Joshua Horan

LRDC, University of Pittsburgh• Gaea Leinhardt• Jim Greeno • Karen Evans• Baohui Zhang

Thanks To

Funding• NSF: CCLI, NSDL, SLC • William and Flora Hewlett

Foundation • Howard Hughes Medical Institute• Dreyfus Foundation

what is conceptual learning in chemistry and why should we promote it?

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