Chapter 2: How is Personality Studied and Assessed? This multimedia product and its contents are protected under copyright law. The following are prohibited by law: (1) Any public performance or display, including transmission of any image over a network; (2) Preparation of any derivative work, including the extraction, in whole or in part, of any images; (3) Any rental, lease, or lending of the program. Copyright © 2012 Pearson Education, Inc. All rights reserved. Copyright © 2012 Pearson Education, Inc. All rights reserved.

Subjective Assessment Measurement that relies on interpretation (unlike objective assessment) Weaknesses Different observers may make different judgments Strengths Complex phenomena may be examined and valuable insight gained Copyright © 2012 Pearson Education, Inc. All rights reserved.

Reliability (1) The consistency of scores that are expected to be the same Test-retest reliability Measure of consistency over time Copyright © 2012 Pearson Education, Inc. All rights reserved.

Reliability (2) Internal consistency reliability Split-half reliability The correlation between two halves of a test Cronbach’s coefficient alpha The average of all possible split-half correlations Copyright © 2012 Pearson Education, Inc. All rights reserved.

Validity (1) Construct validity Convergent validity The extent to which a test truly measures a theoretical construct Convergent validity A measure is related to what it should be related to Discriminant validity A measure is not related to what it should not be related to Copyright © 2012 Pearson Education, Inc. All rights reserved.

Validity (2) Criterion-related validity Content validity The measure can predict important outcome criteria Content validity The measure contains items that represent the entire domain of the theoretical construct Copyright © 2012 Pearson Education, Inc. All rights reserved.

Item Selection Items should be clear and relatively simple Items should discriminate among test takers Items should be intercorrelated But not so highly that they are redundant The total score of the assessment should have a normal distribution Avoid ceiling and floor effects Be sensitive to variability across the range of scores Copyright © 2012 Pearson Education, Inc. All rights reserved.

Response Sets (1) A bias in responding to test items that is unrelated to the personality characteristic being measured Acquiescence response set “yes”, “agree,” “true of me” Social desirability response set The “good” or “correct” answer The answer that reflects well on the test-taker Copyright © 2012 Pearson Education, Inc. All rights reserved.

Response Sets (2) To reduce the problem of response sets Reverse-code some items Use neutral wording Include lie scales Use several different methods of assessment Copyright © 2012 Pearson Education, Inc. All rights reserved.

Ethnic and Gender Bias A characteristic that is a strength in one group may be perceived as a weakness or deficiency in another All tests make assumptions about the background of the test-taker Use care in interpreting results Always consider the context Copyright © 2012 Pearson Education, Inc. All rights reserved.

Types of Personality Measures: Self-Report Tests Usually pencil and paper tests Most common type of test Examples: Minnesota Multiphasic Personality Inventory (MMPI) Big-Five Inventory (BFI) Affective Communication Test (ACT) Copyright © 2012 Pearson Education, Inc. All rights reserved.

Types of Personality Measures: Q-Sort Tests Person makes comparisons among his/her own characteristics Uses a stack of cards, one characteristic per card Sorts cards into piles indicating how descriptive each card is of him/her Forced number of cards at each level Normalizes use of levels across test-takers Copyright © 2012 Pearson Education, Inc. All rights reserved.

Types of Personality Measures: Judgments by Others Someone else answers questions about the person being measured Some traits are easier to judge than others Can use ratings from parents, friends, teachers, spouse, psychologists, etc. Used for adults and children Copyright © 2012 Pearson Education, Inc. All rights reserved.

Types of Personality Measures: Biological Measures Assumes that the nervous system is an important element of personality Modern biological measures Electroencephalogram (EEG) Can provide event-related potentials (ERPs) Positron emission tomography (PET) scan Magnetic resonance imagery (MRI) Functional magnetic resonance imagery (fMRI) Hormonal levels Chromosomal analysis Copyright © 2012 Pearson Education, Inc. All rights reserved.

PET Scan Brain in REM Sleep (horizontal view, nose on top) Lightest areas have highest activity Copyright © 2012 Pearson Education, Inc. All rights reserved.

Types of Personality Measures: Behavioral Observations Records the actual behavior of a person Types of behavioral observations Simple counts of a specific behavior Coding videotaped interactions Electronic pagers Copyright © 2012 Pearson Education, Inc. All rights reserved.

Types of Personality Measures: Interviews Unstructured interviews Typically yield rich information, but validity is questionable Structured interviews More valid, but usually do not reveal individual nuances Copyright © 2012 Pearson Education, Inc. All rights reserved.

Types of Personality Measures: Expressive Behavior The analysis of how people stand, move, speak, etc. Includes the examination of: speech rate voice quality gaze patterns posture gestures Copyright © 2012 Pearson Education, Inc. All rights reserved.

Types of Personality Measures: Document Analysis/Life Stories Involves the careful analysis of writings such as letters and diaries Can be a very rich source of information Examples: Allport’s “Letters from Jenny” Terman’s analysis of Galton’s letters Copyright © 2012 Pearson Education, Inc. All rights reserved.

Types of Personality Measures: Projective Tests Present an unstructured or ambiguous stimulus, task, or situation Test-taker provides an interpretation The goal is to gain access to unconscious motives and concerns Examples: Draw-a-person test Rorschach Inkblot Thematic Apperception Test (TAT) Copyright © 2012 Pearson Education, Inc. All rights reserved.

Projective Test Example: Draw-a-Person Drawing by a nine-year-old in response to the prompt “Draw a person” Copyright © 2012 Pearson Education, Inc. All rights reserved.

Projective Test Example: Inkblot An inkblot stimulus similar to those used in the Rorschach Test. The test-taker is asked, “What do you see?” Copyright © 2012 Pearson Education, Inc. All rights reserved.

Types of Personality Measures: Demographics and Lifestyle Uses information about a person’s age, place of birth, gender, family size, etc. Can help researchers understand people based on their everyday lives Copyright © 2012 Pearson Education, Inc. All rights reserved.

The Ethics of Personality Testing Test results always contain some error However, this should not prevent us from using personality tests Due to these errors, one must be careful when interpreting test results when choosing how to apply the results Copyright © 2012 Pearson Education, Inc. All rights reserved.

Research Designs Common designs in personality research: Case Studies Correlational Studies Experimental Studies Each has different benefits and drawbacks Copyright © 2012 Pearson Education, Inc. All rights reserved.