Title

A Psychometric Evaluation of the Revised Optimism-Pessimism Scale of the MMPI-2

Date of Award

2009

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Psychology

First Advisor

William Goggin

Advisor Department

Psychology

Abstract

The present study tested the psychometric properties of the Revised Optimism-Pessimism Scale (PSM-R) of the MMPI-2. This scale purportedly measures the respondent's explanatory style on a dimension of optimism and pessimism. Participants included 92 college undergraduates and 2,729 participants from archived outpatient data. The PSM-R is a reliable measure, based on test-retest reliability and internal consistency. However, the construct validity of the measure is questionable. Evaluation of the PSM-R items suggests that the items are not all related to the optimism-pessimism construct. In addition, convergent validity of the PSM-R was assessed using measures of attributional style, dispositional optimism, hope, depression, neuroticism, extraversion, and positive and negative affect. Discriminant validity was assessed using measures of social desirability and self-consciousness. The PSM-R was significantly correlated with all of these validity measures, except attributional style. The pattern of results with these measures and the PSM-R resembled the results of the dispositional optimism measure, rather than that of attributional style. Results from the principal components analysis suggest that the PSM-R does not contain a single factor of optimism-pessimism, but rather contains several factors, some of which are unrelated to the construct of optimism-pessimism. The extracted principal factor is a more pure form of optimism-pessimism, based upon evaluation of the items within the factor, and the correlations between this factor and the other measures of optimism-pessimism. The extracted principal factor appears to resemble dispositional optimism-pessimism rather than explanatory style optimism-pessimism. Current findings suggest that the PSM-R is not accurately measuring what it claims, and use of the measure is questionable as psychometric research on the measure continues.