Because of a change in prison policy which greatly reduced the potential subject pool, only six of the ten MMPI types could be compared (from least to most severely disturbed: Able, Item, Easy, George, Delta, and How). Nevertheless, the success rate of classifying subject profiles was high in both the general population sample (114 of 116, or 98.3 percent) and the MHU sample (57 of 63, or 90.5 percent). Subjects from the general population tended to be better adjusted, while MHU subjects fell disproportionately into the How group. This finding is consistent with that of other research and demonstrates MMPI's sensitivity in measuring the varying degrees of pathology. Important legal, prison, and corrections decisions are made based on such assessments. Ten chapters cover the background of the research problem and the context into which the MMPI typology fits, its rationale, methodology, data review, conclusions, and implications. Tables, 4 appendixes, 95 references.