The prediction of premorbid memory ability.

An estimation of premorbid memory ability is necessary for clinical judgments of memory status following brain injury or illness. This paper describes the nature of clinical reasoning about memory ability and intelligence. The analysis of these reasoning problems has progressed from the simple contrast of clinical versus actuarial models to a theory that integrates all such models as applications of reasoning under uncertainty. This is followed by the first empirical study of the estimation of premorbid memory ability from demographic variables. The results of this analysis clearly suggest that demographic variables predict memory scores at a low level (R =.45); this result stands in contrast to the higher predictive power of demographics when IQ is the criterion. Practical suggestions are then proposed for establishing an empirical basis for clinical judgments of premorbid memory ability.