ABSTRACT
Diagnosis of neuropsychological deficits has, until recently, mostly depended on the depth and breadth of clinical experience of the neuropsychologist (Reynolds, 1989). Traditional neuropsychological assessment instruments frequently had little or no published psychometric information or norm tables. Those that did include psychometric information or norms of some description were often basing that information on so small a sample as to make it statistically unstable and unreliable, and therefore unusable for the population at large. The feeling among neuropsychologists was apparently that new clinicians eventually would come to know what a deviant score was simply from experience and from "developing" personal norm tables in their heads.
