Psychometric Properties of the Minnesota Multiphasic Personality Inventory–Adolescent (MMPI–A) Clinical, Content, and Supplementary Scales in a Forensic Sample

Abstract

In this study, we evaluated the internal psychometric properties and external correlates of scores on the Clinical, Content, and Supplementary scales in a forensic sample of 496 adolescents (315 boys and 181 girls) who were court-ordered to receive psychological evaluations. We examined Cronbach's alpha coefficients, scale intercorrelation matrices, and frequencies of scale elevations. Further, we found varying degrees of support for the convergent and discriminant validity of scores on the MMPI–A (Butcher et al., 1992) Clinical, Content, and Supplementary scales. This study adds to the body of literature establishing the utility of the MMPI–A in forensic evaluations.

Acknowledgments

This research was supported by grants from the University of Minnesota Press and the Benjamin R. Brown and Charles G. Brown funds of the Hampton Roads Community Foundation.

John A. Mason is now at the Hampton VA Medical Center, Hampton, Virginia. Elise C. Simonds-Bisbee is now at the Durham VA Medical Center, Durham, North Carolina.

Preliminary analyses, based on a subset of the current data set, were presented at the 2007 Society for Personality Assessment Annual Meeting, Arlington, Virginia.

Notes

In Table 1, individual DSM–IV–TR diagnoses were combined into broader categories. A full description of the diagnoses included in each category listed in Table 1 is available from the first author upon request.

We inspected bivariate scatter plots for all convergent and discriminant validity coefficients reported in this article. When outliers were found, they were recoded to less extreme values. In no cases did this process result in validity coefficients of considerably different magnitude. Therefore, all validity coefficients reported in this article are based on the actual raw data.