Evaluating the similarity of MMPI-2 and MMPI profiles: reply to Dahlstrom and Humphrey

We review issues that have arisen in exchanges with Dahlstrom and Humphrey (Dahlstrom & Humphrey, 1996; Humphrey & Dahlstrom, 1995) about assessing the comparability of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and the MMPI. We point out the limitations of Q correlations (without contending that D(2) is "the only legitimate function of profile comparability," as Dahlstrom and Humphrey, 1996, p. 350, claim we do), and explain why Dahlstrom and Humphrey's (1996) new Q-correlational results, correctly interpreted, are consistent with our own previous observations and conclusions. We stress again the importance of both overall profile elevation and profile "definition" in making code-type assignments. Nonrestrictive code types ignore these profile characteristics, and their use needlessly lowers MMPI-2/MMPI code-type congruences and raises the incidence of profile misinterpretations. Our recommendation of well-defined MMPI-2 code types stands.