Issues in Personality Assessment Chapter Three Issues in Personality Assessment

Sources of Information Ratings by others Direct report by observer Peer ratings Self-reports Scales—assess a single aspect of personality Inventories—measure several distinct aspects of personality

Implicit Assessment Indirect means of determining what a person is like Example: Implicit Association Test (IAT) People make categorical decisions rapidly Response times can reveal how closely linked different concepts are in a person’s mind

Types of Information Objective: measure of concrete reality that involves no interpretation Example—counts of the time a person touches another in an interpersonal interaction Subjective: measure that involves interpretation Example—evaluation of facial expressions for signs of hostility

Reliability Consistency or repeatability of measurement High reliability = greater consistency = lower randomness (error) Low reliability = less consistency = more error

Types of Reliability Internal reliability: reflects consistency within a set of items intended to measure the same construct Test-retest reliability: reflects consistency of a measure across time

Validity Accuracy of measurement—does it measure what it’s supposed to measure? Types of Validity Construct Criterion Convergent Discriminant Face

Construct Validity Indicates a match between operational and conceptual definitions Most important type of validity Other types of validity help establish construct validity

Criterion (Predictive) Validity Most important indicator of construct validity Examines how well a measure correlates with a standard of comparison (criterion) Example—does an aggression scale correlate with observer ratings of shoving on a playground? Examines how well a measure predicts an appropriate outcome Example—does a self-esteem scale predict who will volunteer answers in class?

Convergent Validity Indicates appropriate correlation with assessment devices presumed to measure the same construct Highly correlated Indicates appropriate correlation with assessment devices presumed to measure conceptually similar constructs Correlated, but not too high, not too low

Discriminant Validity Indicates that scale does NOT correlate with other assessment devices presumed to measure conceptually dissimilar constructs Example: Correlations with Sociability scale Measure Correlation Demonstrates Number of friends .89 Convergent Validity Hours spent alone -.92 Neuroticism .04 Discriminant Validity Conscientiousness -.06

Face Validity Indicates that the item or scale measures what you think it is supposed to measure Examples: Construct Item Depression Do you often feel sad or blue? Optimism Do you generally expect good things to happen?

Culture and Validity Important questions Does construct exist in all cultures? (cultural universality) Are items interpreted the same in each culture?

Classic Representation of Reliability and Validity Not Reliable Not Valid Reliable Valid

Challenges to Validity Memory bias Motivational bias Response sets—readiness to answer in a particular way Yea saying (acquiescence) Nay saying Social desirability

Two Approaches to the Development of Assessment Devices Rational (Theoretical) Approach Start with conceptualization Select items to fit conceptualization Test validity and reliability Empirical (Data-Based) Approach Empirically driven from many items Use statistical methods to select items based on ability of items to differentiate criterion group

Example of Empirical Approach Minnesota Multiphasic Personality Inventory (MMPI) Started with many self-descriptive statements Administered to “normals” and groups with psychiatric diagnoses Items selected for a scale were ones that differentiated a particular psychiatric group from all others

When Are Different Methods Used? Rational Approach Usually in connection with theory building Empirical Usually used in connection with practical needs Example: Vocational interests