1. Basic methods cont. Psych 231: Research Methods in Psychology

2. General research approaches Descriptive: Observational Naturalistic observation Participant observation Contrived observation Survey Case studies Correlational Experimental

3. Observational methods Advantages May see patterns of behaviors that are very complex and realized on in particular settings Often very useful when little is known about the subject of study May learn about something that never would have thought of looking at in an experiment

4. Observational methods Disadvantages Causality is a problem Threats to internal validity because of lack of control Every confound is a threat Lots of alternative explanations Directionality of the relationship isn’t known Sometimes the results are not reproducible

5. Survey methods Widely used methodology Can collect a lot of data Done correctly, can be a very difficult method Doesn’t provide clear cause-effect patterns

6. Case Histories Intensive study of a single person, a very traditional method Typically an interesting (and often rare) case This view has a number of disadvantages There may be poor generalizabilty There are typically a number of possible confounds and alternative explanations

7. Correlational Methods Measure two (or more) variables for each individual to see if the variables are related Used for: Predictions Reliability and Validity Evaluating theories Problems: Can’t make casual claims

8. Causal claims We’d like to say: (variable X) causes (variable Y) To be able to do this: 1. The causal variable must come first 2. There must be co-variation between the two variables 3. Need to eliminate plausible alternative explanations

9. Causal claims Directionality Problem: Airplanes and coffee spills One might argue that turbulents cause coffee spills One might argue that spilling coffee causes turbulents

10. Causal claims Happy people sleep well Or is it that sleeping well when you’re happy? Third variable problem: Do Storks bring babies? A study reported a strong positive correlation between number of babies and stork sightings Directionality Problem: Airplanes and coffee spills

11. Theory 1: Storks deliver babies

12. Theory 2: underlying third variable

13. The experimental method Manipulating and controlling variables in laboratory experiments Must have a comparison At least two groups (often more) that get compared One groups serves as a control for the other group Variables Independent variable - the variable that is manipulated Dependent variable - the variable that is measured Control variables - held constant for all participants in the experiment

14. The experimental method Advantages Precise control possible Precise measurement possible Theory testing possible Can make causal claims

15. The experimental method Disadvantages Artificial situations may restrict generalization to “real world” Complex behaviors may be difficult to measure

16. Next time Exam 1