APA Dictionary of Psychology

a method for separating conscious (or intentional) and nonconscious (or automatic) uses of memory and for producing estimates of the isolated contributions of recollection and familiarity to memory performance. Based on the idea that no test of memory is process pure—that is, performance on any test is likely to result from both conscious and nonconscious memory processes—the PDP works by placing these two processes in opposition. After an initial study phase, the PDP uses an inclusion test, during which participants are instructed to respond to the cues (e.g., word stems) with previously studied words, and an exclusion test, during which participants are instructed to respond to the cues with any word that comes to mind except the previously studied words. It is assumed that both recollection, which is intentional, and familiarity, which is automatic, contribute to memory performance on the inclusion test, but that the production of a previously studied item on the exclusion test must result only from familiarity. Using a series of equations, estimates for recollection and familiarity can be obtained. In addition to this general logic, the PDP depends on several assumptions (e.g., that the two processes are independent). Also called method of opposition; process-dissociation method. [developed by U.S. psychologist Larry L. Jacoby (1944–  )]