The discrimination of patient-generated and randomly generated MMPIs

A discriminant analysis was applied to 34 randomly generated and 34 patient-generated Minnesota Multiphasic Personality Inventory (MMPI) profiles. The discriminant was able to differentiate the two sets at greater than 97% accuracy. A cross validation based on derived unstandardized canonical discriminant functions was carried out on an additional 10 random and 10 patient MMPIs. It attained 95% accuracy. Eight experienced clinical psychologists attained less than 70% accuracy--six of the eight did no better than chance. The importance of including actuarial data in validity judgments was discussed.