Criterion-related validity and stability: equivalence of the MMPI and the MMPI-2

The differential criterion-related validity of the MMPI and MMPI-2 and their stability over a 4-month period of time were examined in a university population by correlating the clinical scales with their counterpart SCL-90-R factors. Fair to moderate correlations were found on all eight paired MMPI scales and SCL-90-R factors, while only two of eight MMPI-2/SCL-90-R pairings were found to be correlated significantly. Further analyses, however, found no significant differences between these MMPI/SCL-90-R and MMPI-2/SCL-90-R correlations. Adequate stability was found between MMPI-2 and SCL-90-R pairs over 4 months, except for the MMPI-2 D scale with the SCL-90-R Depression factor. Several issues related to the equivalency between the MMPI and the MMPI-2 were discussed.