Exclusion of learned material from recall as a postretrieval operation

Three experiments are reported in which, following presentation of a categorized list, subjects either recalled the whole list or a part of the list other than words in specified categories or those beginning with certain letters. Instructions to exclude part of the list from recall did not improve recall of the remainder, regardless of whether the exclusion instructions were based on the semantic dimension (category names) or the graphemic dimension (initial letters). The results suggest that it is difficult to retrieve selectively parts of a studied list from memory when recall instructions specify only what not to recall. This fact can be interpreted by assuming that retrieval is a consequence of matching information from two sources, the memory trace and cues in the retrieval environment.