The Role of Rehearsal in Short-Term Memory

Abstract Fergus I. M. Craik and Michael J. Watkins conducted two experiments which oppose many widely accepted models of memory, stating that an items length of stay in short term storage (STS) has an effect on the item being transferred into long term storage (LTS). Previous researchers postulate the more an item is rehearsed in STM there is a better chance of the item being transferred into LTM, for recall later, this can explain the negative recency effect in free recall; items presented at the end of a list are not rehearsed as often, being poorly retrieved later. Craik and Watkins experiments showed that neither the amount of time an item stayed in STM nor the number of overt rehearsals was related to subsequent recall (Craik and Watkins). They have concluded that the maintenance and elaborative aspects of the rehearsal can by separated. Maintenance does not lead to an improvement in memory performance (Craik and Watkins).
Experiment # 1 Participants in this experiment were instructed to listen to a series of word lists, reporting only the last word beginning with a specific (critical) letter after each list was completed. The participants were given the critical letter prior to the presentation of the list, therefore able to ignore all other words not containing the critical letter. Once another word with the critical letter was presented the participant could drop the first word and rehearse the next. Continuing until the list ended. Once the list ended the participant wrote down the last critical word. Three rates of presentation were used; the time a critical word was held in STS varied both as a function of presentation rate, and the number of noncritical words monitored between presentation and replacement (Craik and Watkins). Following the presentation of all the lists, participants were unexpectedly asked to recall as many words as possible from all the lists presented previously. For each rate of presentation, the delayed recall of both the