Intratest and Intertest Means and Reliability of the MMPI–168 for University Students and Patients Referred for Neuropsychological Assessment

68 first-year university students and 37 patients, after a 1-mo. or a 2-yr. interval, respectively, were re-administered the MMPI–168 (the first 168 items of the Minnesota Multiphasic Personality Inventory). The mean of the test-retest correlation coefficients between the first and second administrations for the 13 scales (3 validity, 10 clinical) was about .62 for the students and the patients. The mean absolute change in standardized scores for the scales between the two administrations for both groups was only 0.2 of a standard deviation. Compared to the students, however, the patients who had been referred for neuropsychological assessments displayed elevated (>2 SD) mean scores for several of the scales during both administrations. These results indicate that the MMPI-168 profiles of the patients did not change appreciably even though several years had elapsed since the injuries. The correlation coefficients between means of the scaled scores between the first and second administrations for the students and patients were .91 and .95, respectively.