Chapter 2 Research Methods

ETHICS IN RESEARCH

APA GUIDELINES: Research must be approved by ethics board or institutional review

board (IRB)If research doesn’t meet APA criteria, the researcher will be asked

to revise and resubmit work.

Animal Research-APA

1. Clear Scientific Purpose

2. Humane Care

3. Legal Acquisition

4. Minimal Suffering in Experiment

Human Research

1. Informed Consent

2. Deception

3. Coercion

4. Anonymity

5. Risk

6. Debriefing

Regardless of the method used, all research is based on the Scientific Method of Psychology

Scientific method(s)Scientific means systematic,

testable, and objective.

Essential Question

What are the three main principles that guide the Scientific Method of Psychology?

Simplified Scientific Method

Step 1 – TheoryStep 2 – HypothesesStep 3 – Research and Observation

Step 1

Theories organize known facts and summarizes current research in the field. What do we already know?

Step 2

A hypothesis is then created as a testable prediction based on what is currently known and what we want to find out. What do we want to know more about?

Step 3

Research or observation or experiments are generated to collect data, which then goes into evaluating the hypothesis, which may or may not add to the existing theory. What did we find out?

What are some examples of research methods?

I. Naturalistic Observation

Study behavior in its natural context. Spontaneous behavior in a subject’s natural environment. No interaction with the subject.

IE. If you want to study the interactive behavior of a specific breed of gorillas, you would need to go to where the gorillas live in nature (not a zoo). You would need to observe them without their knowledge, and without manipulating anything.

II. Case Study

A case study is one type of observational data collection technique in which one individual is studied in-depth in order to identify behavioral, emotional, and/or cognitive qualities that are universally true, on average, of others. Case studies often include face-to-face interviews, paper and pencil tests, and more.

Why use a case study?

IE. I want to know why Bart killed thirty-five people over a twenty-year period of time. I will examine the police files, observe and interview Bart, talk to his and the victims families, etc.

III. Survey

Questionnaires/ interviews. Getting a large amount of information from a large group of people.

When Creating A Survey

Questions need precise answersLanguage and wording must be simple

IE. 77% of New Yorkers were interested in plants and trees, but only 39% were interested in botany; 48% were interested in fossils, but only 39% were interested in paleontology; 42% were interested in rocks and minerals, but 53% were interested in Geology

Wording Is Key

Example: “abortion” or “Pro-Choice”“unborn child” or “fetus”Wording must be as neutral as possibleGroups conducting research should be neutral-avoid confirmation bias

When Creating A Survey

Ask questions that won’t embarrass or humiliate

Responders will lie if there is a perceived punishment or reward– Anonymity is key

Don’t ask morally ambiguous questions – keep it simple and to the point

Who the interviewer is will affect the responders answers-gender, affiliation, etc.-expectations?

When Creating A Survey

Shortly phrased questions. IE. As you know, the term Holocaust usually

refers to the killing of millions of Jews in Nazi death camps during WWII. Does it seem possible or does it seem impossible to you that the Nazi extermination of the Jew never happened?

1 out of 5 Gallup poll responders said that the Holocaust never happened due to the phrasing of the question

When Creating A Survey

Hot Topics/Key Words:IE. Do you favor an

amendment prohibiting abortions? >50% opposed OR Do you favor an amendment protecting the life of an unborn child? <30% opposed it

When Creating A Survey

Limited Answer OptionsOrder of Questions – easier to more

difficult works bestFright Terms – avoid using terms with

big repercussions IE. Problem V. Crisis, Passed away V.

Dead, Dealt With V. Punish

False Consensus Effect

Tendency to overestimate the extent to which others share our beliefs and behaviors. Skews the reports by jumping to large conclusions that fit into our pre-conceived ideas.

IV. Experiment

An investigation seeking to understand relations of cause and effect. The experimenter changes a variable (cause), and in turn changes another variable (effect). At the same time the experimenter hopes to hold all of the other variables constant so that they can attribute any changes to the manipulation.

How do I create a valid and reliable experiment?

Step 1: Choose a Hypothesis

A hypothesis expresses a relationship between two variables.

IE. My hypothesis is that watching violent television programs makes people more aggressive.

Step Two: Choose Variables

Variables are things that are measured, controlled, or manipulated in research.

The independent variable is the manipulated variable.

IE. Watching television violence is the independent variable because I can adjust what shows are viewed, for how long, by whom, etc.

The dependent variable is measured for change.

IE. Measuring the change in aggression levels is the dependent variable in our experiment because it changes based on what is viewed, for how long, etc.

Step Three: Operationalize

When you operationalize your variables, you are explaining how you will measure them.

IE. The operational definition of the independent variable (what defines a violent show?) would be shows that have scenes of fighting, bloodshed, use of weapons, injury, kicks, punches, etc.

IE. The operational definition of the dependent variable (what constitutes an increase in aggressive behavior?) would be an increase in agitation or tenseness, increased vocal volume, threats of bodily harm, kicks, punches, throwing objects, etc.

Step Four: Identify Potential Extraneous Variables/Confounding Variables

It is important to make sure that during the experiment as many other factors that are NOT part of the therapy are NOT included. Any factor or variable that causes an effect (or potential affects) other than the variable being studied is considered an extraneous variable.

IE. An extraneous variable in our experiment would be a phone call from a solicitor during a program, the viewer receiving mail including a poor report card, a viewer stubbing their toe during a show, alcohol abuse, etc. All of these could increase aggressiveness, but are not related to viewing violent television.

Step Five: Identify Who You Will Be Testing

The individuals on which the research will be conducted are called subjects (or participants).

A small group of subjects are drawn from a larger potential population.

IE. Our subjects will be drawn from the overall population of 12th grade males at Phoenixville Area High School.

Step Six: How Do We Decide Who Will Be Subjects, and Who Won’t?

Since we can’t realistically test all 12th grade males at Phoenixville Area High School, we have to create a representative sample of the population so that we can generalize our findings to the whole group.

Method 1: Rigorous Control Design

Designing an experiment with specific, hand-picked groups in mind.

IE. Only testing males, 18 years old, in AP Psychology.

Method 2: Sample Design

A sample is a representation of the entire population.

A random sample allows that every member of an overall population has an equal chance to be in the sample.

IE. Drawing names from a hat.

Method 3: Stratified Sample

Subdivide the population into at least two different subpopulations that share the same characteristics, then draw a random sample from each group.

IE. Surveying views on Equal Rights. Split your human population into men and women, and then randomly draw eight men’s and women’s names.

Method 4: Systematic Sample

Select a starting point from your population and then select every ?th participant.

IE. Merck corporation wants test the effectiveness of a new aspirin on their 100,000 employees. Get a roster of employees, start at #1, and then choose every 100th name on the list.

Method 5: Cluster Sampling

Divide your population into multiple subgroups, randomly choose a subgroup to test, and then test the entire population of that subgroup.

IE. Split the country up into geographic regions (East Coast, Midwest, etc.). Randomly choose a region to test, and then test every person in those states.

Method 6: Convenience Sampling

Use a population that is readily available.

IE. Test your neighbors, your family, your co-workers, a passer-by on the street.pd1 stop

Step Seven: Assignment

Once you have chosen your subjects to study, you must assign them to one of two groups; those that will be manipulated, and those that won’t.

Group 1: Experimental Group

The experimental group receives the independent variable and is manipulated throughout the experiment.

Group 2: Control Group

The control group does not receive the independent variable.

IE. In our television violence experiment, those in the experiment group will watch varying degrees of violent program, for varying lengths of time, etc., and their changes in levels of aggression measured.

IE. In our television violence experiment, the control group will be shown a variety of non-violent programming in order to create a baseline to compare the experiment group against.

Steps to follow for an experiment

1. choose hypothesis 2. choose variables 3. operationalize 4. identify confounding variables 5. identify subjects/population to be tested 6. Who will be tested? Sampling 7. Assignment 8. Address other issues/bias/flaws

Method 1: Random Assignment

Random assignment means that the subjects have an equal chance of being placed into each group. If we allow subjects to choose their own group, we may have a subject-relevant confounding variable.

Subject-Relevant Confounding Variables

A subject-relevant confounding variable would allow those people that liked violent movies or were prone to violence already to choose to be in the experimental group. We therefore could not accurately find that viewing violence led to aggression.

To help avoid this confounding variable, we prescribe a single-blind design. The subjects do not know whether they have been randomly placed in the control or experiment group.

Method 2: Group Matching

When assigning members to the experiment or control group, it is important that the characteristics of both groups need to be as similar as possible.

IE. After rigorously or randomly determining our subjects, as many white, black, tall, short, overweight, slim members should be in the control group as there are in the experiment group.-easy if it is a large group. Difficult if small

Step Eight: Address Other Potential Issues With Experiments

Situation-relevant confounding variables refer to making sure that the situations that the experiment and control groups are placed in are exactly the same. We must have equivalent environments.

IE. We cannot have those watching violent films in a large auditorium, and those viewing sitcoms in a cramped, warm, loud, smelly, or otherwise unpleasant atmosphere.

Experimenter Bias

Experimenter Bias occurs when the experimenter unconsciously treats members of the control and experiment groups differently, which increases the chances of confirming their hypothesis.

IE. The experimenter gives soda to the control group, and beer to the violent viewers. The experimenter speaks more abruptly with the violence crowd (inciting them?).

To help avoid this type of confounding variable, we employ a double-blind design, where neither the subjects nor the researcher may know which is the control or the experiment group. A third-party has the appropriate records so that the date can be analyzed later.

The Hawthorne Effect refers to the fact that some subjects will alter their behaviors simply because they know that they are part of an experiment, regardless of what is being done to them.

The Placebo Effect refers to the phenomenon that a patient's symptoms can be alleviated by an otherwise ineffective treatment, apparently because the individual expects or believes that it will work.

Hindsight Bias is the tendency to believe, once the outcome is already known of course, that you would have foreseen it…that even though it's over and you know the outcome, you knew it all along.

Overconfidence occurs when we tend to think that we know more than we do. -generalizations when reporting results, forcing results into preconceived hypothesis to say “I told you so”, instead of letting the results speak for themselves, etc.

REMEMBER !!!

Only experimental data can conclusively demonstrate causal relations between variables (A causes B to happen).

V. Correlation Study

A correlation study is a statistical measure of the relationship between two or more variables without assigning a cause and effect relationship.

Correlation Study

You cannot conclude a cause and effect relationship from this statistical analysis; you can only imply or predict a strong or a weak relationship between variables !!!

IE. Student scores on the SAT are collected, as are senior year GPA’s. We want to see if a high GPA correlates to a high SAT score. We can’t say one causes the other, but we can imply that students who have high/low GPA’s score high/low on SAT’s. Can we use GPA as a predictor of SAT performance?

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Once I have completed my research, how do I present my findings ?

Skip to 93 graphing data

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Descriptive Statistics

Descriptive Statistics describe a set of data.

If I want to report findings from an observation or a survey, I may want to use a frequency distribution.

A frequency distribution may be a simple chart, a list, or a graph.

A graph of information always plots the frequency along the y-axis, and the subject of the graph along the x-axis.

Measures of Central Tendency

Measures of central tendency provide statistics that indicate the average or typical score in the distribution. There are three measures of central tendency:

MeanMedianMode

Mean

The mean is the arithmetic average of all the scores in the distribution. It is calculated by adding all the scores in the distribution and then dividing this sum by the number of scores.

Median

The median is the middle score of the distribution, the point that divides a rank-ordered distribution into halves containing an equal number of scores. Thus 50% of the scores lie below the median and 50% lie above the median.

Mode

The mode is simply the score in the distribution that occurs most frequently.

The Bell curve- “normal range”

Graphing Measures of Central Tendency

When graphing the mean, median and mode of a distribution, roughly speaking, a distribution has positive skew if the right tail is longer and negative skew if the left tail is longer.

Positively Skewed

This distribution has a positive skew. Note that the mean is larger than the median.

IE. In a neighborhood of relatively low incomes, a few millionaires move in. Those few high salaries will inflate the mean (average), but the median will remain relatively low.

Negatively Skewed

This distribution has a negative skew. The median is larger than the mean.

IE. In a particular well-to-do neighborhood, a few low-income residents move in. The overall average income will drop a bit, but the median will remain relatively high.

Measures of Variability

Measures of variability show how spread out the distribution of scores is from the mean, or how much dispersion or scatter exists in the distribution. If there is a large degree of dispersion, that is, if the scores are very dissimilar, we say the distribution has a large or high variability, or variance. If the scores are very similar, there is a small degree of dispersion and a small variance.

Measures of Variability

RangeStandard Deviation

Range

The range is simply the numerical difference between the highest and lowest scores in the distribution.

Standard Deviation

The measure of variability used most often in research is the standard deviation, a statistic that indicates the average distance of the scores from the mean of the distribution.

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IE. Our class took Unit Exam 2. I scored a 76%. I want to know how well I did in relation to the rest of the class to see whether or not that score was good or bad. I need to figure out what the class average was, figure out the standard deviation from the mean, and I’ll know how well I did.

Standard Deviation

Graphing Standard Deviation

Find the mean of your distribution set.Calculate the SD on your calculator.The mean is set at “0”. +1 and -1 are your SD above and below

the mean. IE. Your mean is 56 with a SD of 6. +1

would be 62, and -1 would be 50.Calculate +- 2 and +- 3 in the same manner.

Graphing Standard Deviation

What does this tell us? If the mean of a set of class scores on a unit

exam was 72, with a SD of 8, 68% of students scored between a 64 and an 80. Your score of a 76 would be close to being better than 68% of the rest of the class.

Approximately 95% of the class scored between a 56 and an 88. Your score of a 50 would indicated that roughly 96% of the class did better than you on the test.

Graphing Data

Scatterplot – A graphed cluster of dots that represent the values of two variables.

The SLOPE of the points suggests whether there is a positive, negative, or non-existent relationship between two variables.

POSITIVE CORRELATION – as one set of scores increases, so does the other

NEGATIVE CORRELATION – as one set of scores goes up, another set goes down

NO CORRELATION

How closely the dots are to each other along the line indicates the strength or weakness of the correlation as well

No correlation relates to a score of 0.00

A positive correlation ranges from 0.00 to 1.00

A negative correlation ranges from 0.00 to -1.00 f

Difference between positive and negative?

Worksheet/activity

No more notes please!!