Comparison of linear and configural MMPI diagnostic methods with an uncontaminated criterion.

Suggests that previous studies of linear and configural MMPI diagnostic predictors have suffered from varying degrees of criterion contamination. Previous findings were replicated and extended with 572 male veterans, mean age 37.7 yrs, who were evaluated at the time of application for treatment with the Current and Past Psychopathology Scales. Ss were also administered the Shipley-Institute of Living Scale for Measuring Intellectual Impairment and were diagnostically classified without MMPI contamination. The Goldberg linear equations derived from MMPI group profiles achieved 84% accuracy in classifying group profiles and a 14% increment over base-rate accuracy in classifying individual profiles. The Goldberg linear equation and several configural methods for discriminating psychotics from neurotics were compared. The linear equation was found to be most accurate. Conflicting results in previous articles suggest that criterion contamination must be avoided in prediction studies. A possible use for the group profile classification equations in evaluating experimental studies is suggested. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)