Comparing three new MMPI-2 randomness indices in a novel procedure for random profile derivation.
This study compared three new validity indices; /F-Fb/, VRIN+/F-Fb/, and F+Fb+/F-Fb/; to the F, back-F, and VRIN according to their effectiveness in detecting degrees of profile randomness. Participants completed the Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, and Kaemmer, 1989) according to standardized instructions. All profiles starting at Items 142, 284, or 426 were substituted with computer-generated random responses to produce 75%, 50%, and 25% random profiles, respectively. Twenty-five profiles were derived using 100% computer-generated items. Finally, one unaltered set of profiles was designated as 0% random. This generated five groups of MMPI-2 profiles, differing according to the degree of profile randomness (i.e., 0%, 25%, 50%, 75%, and 100%). Results showed that the F and /F-Fb/ indices were unable to distinguish authentic from all degrees of randomness, whereas the F+Fb+F-Fb scale could reliably distinguish all levels of randomness. The actuarial analysis found back-F and F+Fb+/F-Fb/ misclassified the least number of profiles, suggesting the latter index should be included in the evaluation of MMPI-2 profile randomness.
Cramer
K M
KM
Department of Psychology, University of Manitoba, Winnipeg, Canada.