A comparative meta-analysis of Rorschach and MMPI validity.

Two previous meta-analyses concluded that average validity coefficients for the Rorschach and the MMPI have similar magnitudes (L. Atkinson, 1986; K. C. H. Parker, R. K. Hanson, & J. Hunsley, 1988), but methodological problems in both meta-analyses may have impeded acceptance of these results (H. N. Garb, C. M. Florio, & W. M. Grove, 1998). We conducted a new meta-analysis comparing criterionrelated validity evidence for the Rorschach and the MMPI. The unweighted mean validity coefficients (rs) were .30 for MMPI and .29 for Rorschach, and they were not reliably different (p = .76 under fixed-effects model, p = .89 under random-effects model). The MMPI had larger validity coefficients than the Rorschach for studies using psychiatric diagnoses and self-report measures as criterion variables, whereas the Rorschach had larger validity coefficients than the MMPI for studies using objective criterion variables.