Learning and memory are broad, interrelated categories of behavior and performance that have received enormous attention in experimental psychology. Wide individual differences in learning and memory abilities have long been noted, and have been addressed in psychometric research. Unfortunately, there has been little interplay between experimental and psychometric approaches to these areas, with the result that little can be said about relations between processes studied in experimental investigations and the dimensions of individual differences isolated in psychometric research. In a recent review of memory measures (Richardson–Klavehn & Bjork, 1988) there was no reference to psychometric research, and only a little to individual differences as they occur in the contrast between normal and amnesic subjects.

Learning and memory are related because memory has to do with how the outcomes of learning are retained or forgotten. Nevertheless these categories tend to be treated, both in experimental and psychometric investigations, as if they were separate.