Item-level and scale-level factor structures of the MMPI-A.

The Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A) is a 478-item test that represents a substantial revision of the original form of the MMPI. This investigation sought to identify the item-level factor structure of the MMPI-A and also examined the scale-level factor structure of the 69 scales and subscales of this instrument. The study utilized the 1,620 normal adolescents (805 boys and 815 girls) of the normative sample for the MMPI-A. These adolescents ranged in age from 14 to 18, inclusive, with a mean age of 15.54 for boys and 15.60 for girls. A principal factor analysis of item-level responses resulted in extraction of 14 factors that were subjected to promax (oblique) rotation procedures. These 14 factors incorporated 81% of the total MMPI-A item pool and accounted for 44% of the total item-level response variance. For the scale-level analysis, 8 factors were selected for extraction and submitted to promax rotation procedures. These eight factors accounted for a total of 93.5% of the total variance in MMPI-A scale and subscale raw scores. Item-level results were discussed in terms of areas of congruence and dissimilarities from previously reported MMPI factor analyses in adolescent and adult samples, and scale-level factor results were presented in terms of clinical implications for the interpretation of MMPI-A scales and subscales.