The Equivalence of the MMPI and MMPI-2

Abstract

Since the MMPI-2 was developed, it has been assumed that the new version is comparable to the MMPI. This study explored the comparability of the MMPI and MMPI-2 by examining the similarities between their respective T-score means, profile configurations, score distributions, and rank-order correlations on the standard 3 validity and 10 clinical scales. Eighty-four undergraduate students were randomly assigned to one of four groups in a test-retest (4-month interval) counterbalanced design–MMPI/MMPI, MMPI/MMPI-2, MMPI-2/MMPI, or MMPI-2/MMPI-2. In this college sample, MMPI-2 mean scores tended to be lower than respective MMPI counterpart scales, which is consistent with previous research. There were notable similarities between the MMPI and the MMPI-2 in terms of profile characteristics, score distributions, and rank ordering of scales. Using these criteria, the equivalency of the two forms was generally supported and further equivalency issues are discussed.