Replicated item level factor structure of the MMPI: racial and sexual differences

Item-level factor studies of the MMPI date back to the work of Comrey (1957). Surprisingly, there are no extant studies of the items that clinicians use most in the course of daily MMPI interpretive reporting, namely, the 399 x 399 matrix that represents all of the items that comprise the traditional clinical and validity scales. Furthermore, there are no prior studies with adequate Ns that have examined the replicability of MMPI factor structure via available factor comparison techniques (Harman, 1976). In this study, 20,000 MMPIs were factored by the principal components method, followed by Varimax rotations of 6 through 25 factors. The coefficient of congruence was used to compare the factor structures of randomly divided subsamples, as well as males vs. females and Blacks vs. Whites. Differences in factor structure were found, and suggestions are made with regard to the significance of these findings in clinical and applied settings.