Constituent processes in the differentiation of items in memory.

Three experiments were designed to clarify the perplexing ability of subjects to discriminate between to-be-remembered (TBR) and to-be-forgotten (TBF) items in memory. After the presentation of each pair of words in a list, sub-jects were first required to solve one to four arithmetic problems and were then cued whether to remember or forget that pair. When subjects were free to use a remember (R) or forget (F) cue in any way they saw fit, their subsequent ability to differentiate TBR and TBF items was impressive, but when subjects were required to retrieve both TBR and TBF word pairs in response to an R or F cue, respectively, their subsequent ability to differen-tiate TBR and TBF items deteriorated. The results implicate within-list retrieval of TBR items as a potent tagging or strengthening operation that provides a basis on which those items may later be discriminated from TBF items. The "potency " of such events, in terms of their influence on later recall, depends in a clear-cut way on the "depth " (i.e., delay) of retrieval involved, but there are no such comparable effects on later recognition.