Date of Award
Master of Arts in Psychology
Wayne F. Velicer
The Minnesota Multiphasic Personality Inventory (MMPI) represents the most frequently used and researched personality instrument available today (Edwards and Abbott, 1973). Yet, despite its popularity as a diagnostic instrument in mental health settings, reviewers generally agree that the MMPI is a "psychometric monstrosity" (Rodgers, 1972). The recently developed Basic Personality Inventory or BPI (Jackson, 1974) represents a potential alternative to the presently popular MMPI. The reliability, susceptibility to dissimulation, and discriminant validity of the BPI scales were examined in this study. The BPI was administered to 168 university students and 224 community college students. Data from the first sample (N = 168) was used primarily to conduct an internal consistency and test-retest analysis of the BPI. It was hypothesized that the BPI scales would demonstrate adequate reliability (r ≥ .70). This hypothesis was supported for some scales but not for others. One explanation given for the lower than expected reliability coefficients was the restricted variability observed in the population studied. It was suggested that reliability coefficients based on a clinical population would probably be higher. The observed reliabilities, however, were generally higher than those reported for the MMPI scales. The second sample (N = 224) was used primarily to investigate the faking susceptibility of the scales. It was predicted that mean scale scores for persons receiving standard instructions (n = 124) would be significantly higher than mean scale scores obtained £ran persons receiving "fake good adjustment" instructions (n = 50), and significantly lower than mean scale scores obtained from persons receiving the "fake maladjustment" instructions (n = 50). In general, this prediction was supported. The extent of faking success, however, depended on the scale involved. A stepwise discriminant analysis of this data suggested that three scales, the Deviation scale, the Self Depreciation scale, and the Denial scale could successfully be used as validity scales.
Finally, scale intercorrelations were computed separately for the community college students (standard instructions group only) and both administrations of the BPI to the university students. Scale intercorrelations were examined in an attempt to provide initial evidence of discriminant validity for the twelve BPI scales. It was predicted that near zero scale intercorrelations, and thus good discriminant validity, would be observed. The results, however, were mixed. Evidence of good discriminant validity was obtained from the community college data but not from the university data.
It was concluded that much research still remains to be conducted, rut evidence presented here suggests that Jackson's Basic Personality Inventory (BPI) remains a promising alternative to the presently popular MMPI.
Kilduff, Raymond A., "Reliability, Faking Susceptibility, and Discriminant Validity of the Basic Personality Inventory" (1982). Open Access Master's Theses. Paper 1641.