Control processes in short-term storage: Retrieval strategies in immediate recall depend upon the number of words to be recalled

According to the Atkinson and Shiffrin (1968) model, control processes in the short-term memory store determine the selection ofdifferent storage, search, and retrieval strategies. Although rehearsal is the most studied short-term control process, it is necessaryto specify the different retrieval strategies available for participants to use in searching for and outputting from short-term orimmediate memory, as well as the degree to which participants can flexibly select different retrieval strategies for recallingrehearsed and unrehearsed materials. In three experiments we examined retrieval strategies in tests of immediate free recall (Exp.1), immediate serial recall (ISR; Exp. 2), and a variant of ISR that we call ISR-free (Exp. 3). In each experiment, participants werepresented with very short lists of four, five, or six words and were instructed to recall one, two, three, or all of the items from eachlist. Neither the list length nor the number of to-be-recalled items was known in advance. The serial position of the first itemrecalled in all three tasks depended on the number of to-be-recalled items. When only one or two items were to be recalled,participants tended to initiate recall with the final or penultimate list item, respectively; when participants were required to recallas many list items as possible, they tended to initiate recall with the first list item. These findings show that different retrievalstrategies exist for rapidly searching for different numbers of items from immediate memory, and they confirm that participantshave some control over their output order, as measured by the first items recalled.