Comparison of differential diagnostic discrimination for abbreviated and standard MMPI.

MMPI response protocols for 194 psychiatric patients were scored on the basis of the first 168 items and then on the usual 400 items. The MMPI-168 raw scores were converted to estimates of conventional clinical scale scores. The Ss were divided into 10 major categories on the basis of final clinical diagnosis. Multiple discriminant analysis was used to compare the discriminant validity of the abbreviated and standard scoring. The results indicated no loss in discrimination to result from scoring based on only the first 168 items. Conversion tables that can be used to transform MMPI-168 raw scores to standard MMPI clinical scale scores are presented for further research and clinical use.