1. Studying Behavior

2. Midterm Review Session The TAs will conduct the review session on Wednesday, October 15 th. If you have questions, email your TA and they will prepare a presentation for the review session If nobody emails them questions, Wed. the 15th will be a question & answer session only

3. NONEXPERIMENTAL VERSUS EXPERIMENTAL METHODS Nonexperimental Method Direction of Cause and Effect The Third-Variable Problem (confounding variable)

4. NONEXPERIMENTAL VERSUS EXPERIMENTAL METHODS The casual possibilities in a non-experimental study

5. NONEXPERIMENTAL VERSUS EXPERIMENTAL METHODS Experimental Method Experimental Control Randomization

6. COMPARISON OF NONEXPERIMENTAL AND EXPERIMENTAL METHODS DESCRIPTIONEXAMPLESADVANTAGESDISADVANTAGES NON- EXPERIMENTAL Relationships studied by making observations or measuring variables as they exist naturally Behavior observed as it naturally occurs Asking people to describe behavior Directly observing behavior Recording physiological responses Examining public records Allows measure of covariation between variables IV can be observed in a natural context Allows us to study participant variables that cannot be manipulated Difficult to infer cause and effect Direction and third variable problem Difficult to control many aspects of the situation EXPERIMENTAL Direct manipulation and control of variables, then response or result is observed Measuring behavior then introducing a manipulation and measuring an outcome Random assignment of participants, experimental group experiences manipulation, control group does not, outcome variable is measured Reduces ambiguity in interpretation of results regarding cause and effect Attempts to eliminate the impact of all possible confounding third variables Permits greater experimental control Reduces the possible influence of extraneous variables through randomization High control may create an artificial atmosphere Can be unethical or impractical

7. INDEPENDENT AND DEPENDENT VARIABLES Independent = Cause Dependent = Effect Dependent variable y-axis Independent variable x-axis

8. FOUR TYPES OF RELATIONSHIPS BETWEEN VARIABLES

9. CAUSALITY Inferences of Cause and Effect Require Three Elements: 1.Temporal precedence 2.Covariation between the two variables 3.Need to eliminate plausible alternative explanations

10. CHOOSING A METHOD: ADVANTAGES OF MULTIPLE METHODS Artificiality of Experiments Ethical and Practical Considerations Participant Variables Description of Behavior Successful Predictions of Future Behavior Advantages of Multiple Methods

11. EVALUATING RESEARCH: THREE VALIDITIES Construct Validity Adequacy of the operational definition of variables Internal Validity Ability to draw conclusions about causal relationships from our data External Validity Extent to which the results can be generalized to other populations and settings

12. Critically Evaluating Research Construct ValidityExternal Validity Evaluate the adequacy of the operational definition. Is the operational definition sufficiently measuring the construct it claims to measure? Evaluate the extent that the results can generalize to other populations and settings. Can the results be replicated with other participants? Can the results be replicated in other settings? Internal Validity Evaluate the extent that it was the independent variable that caused the changes or differences in the dependent variable. Are there alternative explanations (confounds)?

13. Multiple Causation We like 1 to 1 relationships, but human behavior is much more complicated Determining one cause doesn’t mean you’ve determined the only cause When more than one variable effects behavior, those variables can interact