III. Research Methods

1. III. Research Methods

2. A. How do psychologists “do” science? • If our intuition, common sense, and folk wisdom is not enough to make valid conclusions about behavior... • Must test our hunches and ideas. • What differentiates psychology from other disciplines (e.g., philosophy).

3. How psychologists “do” science • Typical way psychologists approach a problem: • Make observations, read literature • Come up theory (general explanation). • Develop testable statement (hypothesis) from theory. CAN’T STOP THERE!!! • Pick research method, test hypothesis. • Collect data. See if supports hypothesis.

4. A. How do psychologists “do” science? • Example: Children’s aggression & exposure to violent media. • 1. Theory: • An explanation of phenomenon (using an integrated set of principles that organizes or predicts observations). General claim about behavior. • Example?

5. A. How do psychologists “do” science? • Can’t stop there… • 2. Hypothesis: A testable prediction implied by the theory. Must be a specific & disconfirmable statement. • Example?

6. B. 4 Goals of Psychology • Describe • Predict • Explain • Control/Change

7. C. Goal #1: Describing Behavior • 1. 3 Descriptive Research Methods: • a. Case Studies: Study one or a few individuals in depth. Example: Freud Limits of method?

8. C. Goal #1: Describing Behavior • 1. 3 Descriptive Research Methods: • b. Naturalistic Observation: Observe people in their natural environment. Example: ? Strengths of method Limits of method: - people may change behavior if know being observed.

9. C. Goal #1: Describing Behavior • 1. 3 Descriptive Research Methods: • c. Survey Research: People report behavior, beliefs, or opinions. Examples? Strengths: efficient Limits of method? - i. honesty of reporting. - ii. biases in survey: wording of questions

10. Limits of survey method: • iii. Sampling: who responded to survey. Random Sample: A sample that fairly represents a population because each member has an equal chance of being included in the study.

11. Aggression and watching violent tv... If used one of methods above: • What can we conclude? • What haven’t we addressed (can’t we conclude)?: • What should we be aware of when reading about this research?

12. C. Goal #1: Describing Behavior • 2. Statistics used to depict & interpret data: • If we collect data, what can we do with it? • a. Use graphs to illustrate the data. • b. Summarize data by measures of central tendency. • Mean, median, mode – see text • Is that all? • C. Use measures of variation (dispersion). • Range, standard deviation

13. D. Goal #2: Predicting Behavior • Correlational Research: • 1. Involves measuring behaviors or variables that are already in place. • Could use descriptive methods to get that data. Then... • Apply correlation: Statistical measurement of the extent to which two variables vary together or are associated/related. - how much one variable predicts the other. See overhead:

14. Perfect positive correlation (+1.00) No relationship (0.00) Perfect negative correlation (-1.00) D. Goal #2: Predicting Behavior

15. D. Goal #2: Predicting Behavior • Correlation: Value between 1 and –1 • 2. Two pieces of information correlation statistic provides: • Direction of the relationship (sign of correlation: positive or negative) • Strength of relationship (absolute value of correlation)

16. D. Goal #2: Predicting Behavior • 3. Concerns with correlation: • a. “Reverse Causality” (Cannot determine which variable caused which). • b. The “third variable” problem (Something other than two variables that were measured accounts for the relationship). CANNOT CONCLUDE CAUSALITY

17. D. Goal #2: Predicting Behavior • 4. Strengths/Limits • Strengths: • efficient • study things can’t control/manipulate in laboratory • allows for prediction • Limits: • Problems with descriptive methods • No causality

18. D. Goal #2: Predicting Behavior • Aggression and playing violent videogames: If used correlational research: • What can we conclude? • What haven’t we addressed (can’t conclude)?: • What should we be aware of?

19. E. Goal #3: Explaining Behavior • Experimentation • Creating miniature “drama” or event. • Researcher “manipulates” (“creates”one or more variables/factors vs. correlational research measures existing variables). • Controlled setting.

20. E. Goal #3: Explaining Behavior • 1. Ingredients of an Experiment: Independent Variable: Variable that researcher manipulates. Create an experimental condition. Control Group: Group in experiment that does not receive treatment, or what is manipulated. Serves as comparison group to experimental group.

21. E. Goal #3: Explaining Behavior Dependent Variable: Behavior that is being measured; what is expected to change due to independent variable. Example: independent variables control group (or other group) dependent variable

22. E. Goal #3: Explaining Behavior • 1. Ingredients, cont’d: • Random Assignment: Assigning subjects to experimental or control groups in an experiment by chance, thereby minimizing pre-existing differences between subjects. How? ***** vs. Random Sampling….

23. E. Goal #3: Explaining Behavior • 2. How do we know the differences between experimental conditions are reliable? • Statistical Significance: The difference in the variables is NOT due to chance.

24. 3. Limits of experimentation: • a. Artificiality of lab. • Is it generalizable? • Do people act differently in lab? • b. Ethics • informed consent • debriefing • 4. Strengths of experimentation.

25. E. Goal #3: Explaining Behavior • Aggression and watching violent tv: If used experiment: • What can we conclude? • What should we be aware of?

26. F. Goal #4: Controlling/Changing Behavior • Often involves many steps in process: >Make observations, develop theory, describe phenomenon. > > > Attempt to find variables that are related (correlations) > > > Use that information to develop experiment. > > From your findings, conclude what may be useful in changing/controlling behavior – application.

27. G. Compare/Contrast types of methods... • Are researchers and scientists immune to perceptual biases we’ve discussed?

28. Conclude: • Psychologists have several goals in mind when doing research. • Different research methods are used to address each goal. • Each research methods has its good and bad points. • Important to be aware of what can/can not conclude when using each method.