1. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Measuring the Person Theme and Variation on Topic 2. Research In Personality This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmission of any image over a network; preparation of any derivative work, including the extraction, in whole or in part, of any image; any rental, lease, or lending of the program.

2. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Comparison to Personality: A Systems Approach… Chapter 2: Research in Personality 1.Where Do Data Come From?* 2.What Research Designs are Used in Personality? 3.What Does it Mean to Measure Personality? 4.How do Psychologists Study So Many Variables? Lecture 2: Measuring the Person 1.Collecting data 2.Measuring the person 1.Reliability 2.Validity 3.Simplifying multiple measures

3. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Gathering Data about the Person

4. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Molecular-Molar Dimension (Review) Molar (e.g., sociological level) Intermediate (e.g., psychological level) Molecular (e.g., biological level)

5. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Personality and Its Position: Review Molar (e.g., sociological) The Incorporative Environment Intermediate (e.g., psychological) The Personality System The Situation Molecular (e.g., biological) The Brain and Nervous System The Setting

6. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Two Main Sources of Data Molar The Incorporative Environment Intermed-iate The Personality System The Situation Molecular The Brain and Nervous System The Setting External source data – from outside the person Personal report data – from inside the person

7. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY External Source Data: Examples Molar (e.g., sociological) Institutional Data (School records, Marriage certificates) Intermediate (e.g., psychological) Personality Informant Data (What a friend says about you) Molecular (e.g., biological) Biological Data (Medical records) Setting Data: (Neighborhood qualities)

8. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Major Types of Personal Report Data Molar The Incorporative Environment Intermed-iate The Personality System The Situation Molecular The Brain and Nervous System The Setting Self-JudgmentAgreeing or disagreeing with a given statement about oneself Convergent-ReportConstructing a response that meets a criterion Thematic-ReportCreating responses that reflect themes or ideas Process-ReportPertaining to something going on in your mind at the moment

9. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Measuring the Person (Psychometrics)

10. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Review of Correlation Correlation co-relates… It relates one variable to another The size of the correlation indexes the strength of the relationship r = 1.0 is a perfect positive relationship r = 0 is no relationship r = -1.0 is a perfect negative relationship

11. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Measurement of Attributes Measure attributes of the object For example, measurement of –length (to right) –weight (to right)

12. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Psychometric Theory A.Theories of how to measure abstract, mental phenomena B.The central equation: X = T + e X, the obtained test score T, the true score e, the error score

13. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Reliability in Physical Measurement Things to Remember Measuring a Window for Window Blinds: Use a steel tape for accuracy. Measure the exact width of the window at 3 different places. Make all measurements to the nearest 1/8 inch.

14. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Definitions of Reliability Informal: that a test measures what it measures with consistency Formal: the correlation, r, between the true score and the obtained score.

15. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY (A hard) Pop Question When is a mental test perfectly reliable? A. X = 0 B. T = 0 C. e = 0 D. X = T

16. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Measurement Validity A.Definition: That a test measures what it is supposed to measure B.Types of Validity: 1.Content 2.Criterion 3.Structural 4.Construct

17. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Content Validity A tests items accurately sample from the content domain

18. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Criterion (or Predictive) Validity A test predicts a specific, measurable outcome, such as a life variable Examples: marriage grade point average occupational success (or postdicts it, or concurrently indicates it)

19. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Pop Question A.Which of the following correlations between two variables is most useful for the purposes of predicting one from the other? a) -.75 b).00 c) +.25 d) +.50

20. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Structural Validity A test measure the number of things it claims to measure Technical Test: Factor Analysis… –How many factors does a test measure? –Factor: An underlying variable

21. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Construct Validity A test behaves the way it is supposed to behave according to theoretical statements, over numerous circumstances and tests

22. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Handling Multiple Variables This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmission of any image over a network; preparation of any derivative work, including the extraction, in whole or in part, of any image; any rental, lease, or lending of the program.

23. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Multiple Variables Personality is a complex, multifaceted system This means that a lot of variables may be examined at a time How does one cope?

24. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Multivariate Techniques Multivariate techniques handle multiple variables One crucial kind of technique examines how many things are being measured This class of techniques includes: –Factor analysis (the example here) –Multidimensional scaling –Cluster analysis

25. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Logic of Factor Analysis Factor analysis uses correlational logic –If multiple variables correlate highly, they are the same thing –If the variables dont, they are different things Example: –If happiness and joy correlate highly: the same –If they dont: different

26. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY 1. What does a factor look like? I am:I Curious.40 Interested.60 Thoughtful.80 Bored -.40 The test items from the original test are in the left-most column A factor is represented by a column of factor loadings under a roman numeral The factor loading is the correlation between a test item and a factor

27. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Simplified Rules for Interpreting a Factor Step 1: Identify original test items with high positive loadings Step 2: Ask, what are the items trying to get at? (Thats the primary name of the factor). (e.g., extraversion) Step 3: Locate the items loading negatively on the same factor. Those tell you the polar opposite label (e.g., introversion) – if there is one Step 4: No high loadings? Then, the factor is a garbage factor.

28. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Example A I II Do you like parties?.70 -.15 Are you often nervous?.30.80 Are you sociable?.75 -.01 Do you prefer to read over -.70 -.09 going to parties? Are you often in a bad mood?.04.70

29. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Example B I feel… I II III Happiness.80.20.01 Sadness -.70.10.05 Excitement.60.75 -.10 Anxiety -.25.40 -.15 Calm.20 -.50.20

30. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY Example C I can be described as I II III conscientious.80.20.01 often late-.70.10.05 warm.20.75 -.10 friendly-.25.40 -.15 cold-.20 -.50.20

31. Measuring the Person © Copyright 2006 Allyn & Bacon Mayers Personality: A Systems Approach PART 1: EXPLORING PERSONALITYCHAPTER 2: RESEARCH IN PERSONALITY ~ End ~