Mini Quiz 1. Data that derive from the researcher's direct observation of what the subject does in some predefined context are a. L data. b. I data. c. S data. d. B data.

Mini Quiz 2. _____________________ ask a respondent to interpret a meaningless, ambiguous stimulus in order to access the inner workings of the person's mind. a. Rationally constructed tests b. Projective tests c. Factor analytic tests d. Objective tests

Mini Quiz 3. The basis of the _____________ method of test construction is to come up with items that seem directly, obviously, and logically related to what it is you wish to measure. a. rational b. empirical c. philosophical d. factor analytic

Mini Quiz 4. For any rationally constructed personality scale to work, it must satisfy which of the following conditions? a. The items on the form must all be valid indicators of what the tester is trying to measure. b. The person who completes the form must be willing to accurately report his or her self-assessment. c. Each item must mean the same thing to the person who fills out the form as it did to the psychologist who wrote it. d. All of the above conditions must be satisfied for the scale to work.

Mini Quiz 5) Which one? A) B B) D C) A D) C

Methods for creating a test Rational Method Projective Tests Factor Analytic Method Empirical Method Combination of Methods

Basic Steps 1) Create a test 2) Validate the test 3) Use the test

Statistics

Correlation

Positive Correlation

Positive Correlation

Positive Correlation r = 1.00

Positive Correlation . . . . . r = .64

Negative Correlation

Negative Correlation r = - 1.00

Negative Correlation . . . r = - .85 . .

Zero Correlation

Zero Correlation . . . . . r = .00

Correlation Coefficient The sign of a correlation (+ or -) only tells you the direction of the relationship The value of the correlation only tells you about the size of the relationship (i.e., how close the scores are to the regression line)

Which is a bigger effect? r = .40 or r = -.40 How are they different?

Practice Do you think the following variables are positively, negatively or uncorrelated to each other? Alcohol consumption & Driving skills Miles of running a day & speed in a foot race Height & GPA Forearm length & foot length

Interpreting a Correlation What does it actually mean in “people words”? Binomial Effect Size Display (BESD)

BESD 200 subjects (all sick) Drug given to 100 of them At the end: 100 live and 100 die If the effect of the drug was .00 – what does that mean?

BESD When r = .00 Alive Dead Total Drug 50 100 No Drug 200

BESD 200 subjects (all sick) Drug given to 100 of them At the end: 100 live and 100 die What if the drugs effect was .40 – what does that look like?

BESD When r = .40 Alive Dead Total Drug 70 30 100 No Drug 200

BESD Alive Dead Total Drug 70 30 100 No Drug 200 Thus, if you take the drug you have a 70% chance of living compared to only 30% if you do not take the drug! BESD When r = .40 Alive Dead Total Drug 70 30 100 No Drug 200

BESD How to compute: 200 subjects (all sick) Drug given to 100 of them At the end: 100 live and 100 die Drugs effect was .30

BESD When r = .30 Alive Dead Total Drug 100 No Drug 200

BESD Alive Dead Total Drug 100 No Drug 200 1) Compute cell values if r = .00 BESD When r = .30 Alive Dead Total Drug 100 No Drug 200

BESD Alive Dead Total Drug 50 100 No Drug 200 1) Compute cell values if r = .00 BESD When r = .30 Alive Dead Total Drug 50 100 No Drug 200

BESD Alive Dead Total Drug 50 100 No Drug 200 1) Drop the decimal (30) 2) Divide by 2 (30 / 2 = 15) 3) Add to number in upper left cell (50 + 15 = 65) BESD When r = .30 Alive Dead Total Drug 50 100 No Drug 200

BESD Alive Dead Total Drug 65 50 100 No Drug 200 Plug in value Compute other cell values BESD When r = .30 Alive Dead Total Drug 65 50 100 No Drug 200

BESD Alive Dead Total Drug 65 35 100 No Drug 50 200 Plug in value Compute other cell values BESD When r = .30 Alive Dead Total Drug 65 35 100 No Drug 50 200

BESD Alive Dead Total Drug 65 35 100 No Drug 200 Plug in value Compute other cell values BESD When r = .30 Alive Dead Total Drug 65 35 100 No Drug 200

BESD Practice Create BESDs for the following r = .10 r = .55 r = .80

Correlations Small = .10 Medium = .30 Large = .50

Basic Steps 1) Create a test 2) Validate the test 3) Use the test

Validating a Test Is a test measuring what it is suppose to measure? Not a YES or NO answer Types of Validity 1) Predictive 2) Concurrent 3) Content 4) Construct

Predictive and Concurrent Called “Criterion-orientated” validity Does the test predict some type of criterion? Predictive – criterion is in the future Concurrent – criterion is in the present

Predictive and Concurrent Predicting likeability in Internet Chat Rooms

Participants One-on-One Condition 84 participants 71% female 29% male Markey & Wells, 2002

Likeability * p < .05

Content Validity Test items represent the entire “universe” of possible items

Group Activity What qualities does the trait of extraversion contain? e.g., assertiveness Come up with at least 6 qualities Create one item to measure each quality.

Content Validity Extraversion

Content Validity Positive Emotions Warmth Gregariousness Excitement-Seeking Assertiveness Activity Extraversion

Content Validity Have a lot of fun. Make friends easily Positive Emotions Love large parties Warmth Gregariousness Excitement-Seeking Love excitement. Assertiveness Activity Take charge. Am always busy.

Content Validity Not normally established empirically Established by experts in the field

Construct Validity The test actually gauges the personality dimension being measured. How can you do this? First need to determine if its internal structure is correct.

Content Validity Extraversion

Content Validity Positive Emotions Warmth Gregariousness Excitement-Seeking Assertiveness Activity Extraversion

Construct Validity Next, you need to create a “model” of the construct

Extraversion

Reliable Talking Risk taker Extraversion Eye-contact Stimulation Height

Reliable Talking Risk taker Nomological Net Contains both *Criterion-orientated validity *Discriminant validity Extraversion Eye-contact Stimulation Height

Reliable Talking Risk taker -.04 .60 .54 Extraversion .32 .44 .11 Eye-contact Stimulation Height

Construct Validity Uses all types of validity to determine if a test actually gauges the personality dimension being measured There is actually even more than can be done to examine construct validity -e.g., “changes over time” Note: you NEVER get a single number that represents “construct validity”

Basic Steps 1) Create a test 2) Validate the test 3) Use the test

Basic Steps 1) Create a test 2) Validate the test 3) Use the test Rational Method Projective Tests Factor Analytic Method Empirical Method Combination of Methods 2) Validate the test Predictive Concurrent Content Construct 3) Use the test

What is a trait of personality? A “unit” of measurement Allport presents 8 Criteria that define a personality trait

Traits 1) A trait has more than nominal existence Traits are real!

Traits 2) A trait is more generalized than a behavior lie steal cheat

Traits 2) A trait is more generalized than a behavior lie steal Honesty cheat

Traits 2) A trait is more generalized than a behavior There are systems of behaviors Traits my embrace anywhere between 2 to hundreds of behaviors

Traits 3) A trait is dynamic A trait CAUSES behavior, it is not just a summary of behavior lie steal YES! Honesty cheat

Traits 3) A trait is dynamic A trait CAUSES behavior, it is not just a summary of behavior lie steal NO! Honesty cheat

Traits 4) The existence of a trait my be established empirically or statistically Statistical techniques can be used to examine coherence among behaviors

Traits 5) Traits are only relatively independent of each other It will be difficult to isolate “fundamental” traits that are completely independent of each other

Traits 6) A trait of personality, psychologically considered, is not the same as a moral quality.

Traits 7) Acts, and even habits, that are inconsistent with a trait are not proof of the non-existence of the trait Not realistic to expect perfect consistency Some traits not important in some people Traits interact with each other within a person Context also determines behavior

Traits 8) A trait may be viewed either in the light of the personality which contains it, or in the light of its distribution in the population at large. Some traits are unique and some are universal Can examine either Universal traits across people Unique blends of traits within a person

Using Traits to Understand Behavior Different approaches: The Single-Trait Approach The Many-Trait Approach The Essential-Trait Approach The Simultaneous-Trait Approach