Code-type comparability of the MMPI and MMPI-2: analysis of recent findings and criticisms.

The introduction of the MMPI-2 has stimulated studies of its comparability with the MMPI. Graham, Timbrook, Ben-Porath, and Butcher (1991) consider the congruence between MMPI-2 and MMPI code types substantial, but Dahlstrom (1992) has questioned their appraisal, criticizing their use of "well-defined" code types. Our own analysis supports Graham and colleagues' (1991) conclusions and provides reasons for favoring narrow code types (such as well- defined code types) over nonrestrictive ones. We also offer a brief historical review of MMPI code typology as background for our recommendation that future MMPI-2 research not be limited to studies of code-type correlates.