How can we answer questions about personality scientifically? Personality Research Methods

1. How can we answer questions about personality scientifically?Personality ResearchMethods

2. Self-Identification Survey

3. Personality Research Methods • Goals – • Most generally, to become more sophisticated consumers of research information • To understand how we study personality empirically • To appreciate strengths and weaknesses of various designs and analyses – what they can and can’t tell us about personality • Be able to interpret some key types of statistics

4. Personality Research Methods • What is the purpose of research? • To, as objectively as possible: • Evaluate theories • Answer practical questions • In general, to accumulate knowledge in an objective and public manner

5. Personality Research Methods • Three topics: • Research design • Interpreting data (statistics) • Measurement (personality assessment, already covered)

6. Personality Research MethodsResearch Design • Two broad kinds of questions in research – • 1) Is X related to Y? • Are SAT scores related to GPA scores? • Is emotional expressivity related to physical health? • 2) Does X cause Y? • Does medication cause symptom reduction? • Does child abuse cause Borderline PD? • Do genes determine sexual orientation? • Causality is “the big question”

7. Personality Research MethodsResearch Designs • Types of research design • Experimental • Passive • Case Study

8. Personality Research MethodsResearch Design • Experimental Design – • Manipulate a variable (IV) and measure changes in another variable (DV). • Random assignment to conditions (levels of IV). • Strengths and Limitations - Discuss

9. Personality Research MethodsResearch Design • Passive Designs – • Observe (measure) how pre-existing differences between people on one variable are related to differences between those people on another variable • E.g., drug abuse and psychological adjustment • Why “Passive”? • Strengths and Limitations – discuss

10. Personality Research MethodsResearch Design • Case Studies – • In depth analysis of specific entities (a person, a group, an organization) • Eg, Charles Whitman; Freud - the case of Little Hans; Allport – “Letters From Jenny”; • Strengths and limitations - discuss

11. Personality Research MethodsResearch Design • Personality Psychology often uses Passive Designs • Why? • Is Extraversion related to popularity? • Is Drug Abuse related to psychological adjustment?

12. Personality Research Methods • Three topics: • Research design • Interpreting data (statistics) • Measurement (personality assessment, already covered)

13. Personality Research MethodsInterpreting Data • Statistics are nothing but tools to help us make sense out of data. • We will typically: • Look for group differences on some variable • Look for relationships among variables • At one level, these are the same things.

14. Your BFI Data • A few questions to answer: • Is personality related to happiness? • Are there sex differences in personality? • Is personality related to GPA? • Do these associations/differences differ by trait? • But first – how do we quantify/describe associations/differences?

15. Personality Research MethodsInterpreting Data • Why worry about this? • General sophistication in critical thinking? • Ability to understand studies that we’ll be discussing • Two general kinds of statistics: • Descriptive Statistics • Inferential Statistics

16. Personality Research MethodsInterpreting Data • Two general kinds of statistics: • Descriptive Statistics – • To summarize/describe the data that was collected in a sample of subjects. • Examples – frequencies, means, standard deviations, correlation

17. Personality Research MethodsInterpreting Data • Two General Kinds of statistics (continued) • Inferential Statistics – • To make statements/inferences about the population(s) of people from which the sample of subjects was drawn. • “Statistical significance”. Is the result representative of the “population”? • Male and female samples (20 each) – find difference in IQ. Is this representative of the “population of males and females?

18. Personality Research MethodsInterpreting Data • What is a correlation? • A correlation (r) is a number that summarizes the direction and degree of association between two variables • Do people who have high SAT scores also get relatively high GPAs? • This is a question about the association between two variables: SAT score and GPA.

19. Personality Research MethodsInterpreting Data • A correlation gives two pieces of info: • Direction of association • + people who score relatively high on one variable tend to score relatively high on the other • - people who score relatively high on one variable tend to score relatively low on the other • 0 there is no relationship between the variables - people who score relatively high on one variable are likely to score either high OR low on the other. • Note: “relatively”; “positive” ≠ good

20. Your BFI Data • A few questions to answer: • Is personality related to happiness? • Are there sex differences in personality? • Is personality related to GPA? • Do these associations/differences differ by trait? • But first – how do we quantify/describe associations/differences?

21. Personality Research MethodsInterpreting Data • A correlation gives two pieces of info: • Degree of association • How strongly related are the two variables? • Range from +1 (Very strong positive relationship) to –1 (Very strong negative relationship) • Values closer to zero represent “weaker” relationships So what would a “strong” correlation be? .90? .30? .50?

22. Personality Research MethodsInterpreting Data • Interpreting a correlation – Is this relationship strong or weak? • At least two ways to interpret the size of a corr: • Research context • Translate to Probabilities (BESD, in textbook)

23. Statistical vs Experimental “Control” • What is experimental control? What do we want to “control” when doing an experiment? • What if we can’t do so experimentally? – Statistical control? • “Multiple regression”, partial correlations, etc • Example Conscientiousness, SAT, and GPA

24. Personality Research Methods • Goals – • Most generally, to become more sophisticated consumers of research information • To understand how we study personality empirically • To appreciate strengths and weaknesses of various designs and analyses – what they can and can’t tell us about personality • Be able to interpret some key types of statistics