Relatively few experiments have measured the time course of free recall from episodic or semantic memory. Of those that have, most report that cumulative recall is a negatively accelerated exponential (or hyperbolic) function that is characterized by two properties: asymptotic recall and rate of approach to asymptote. The most common measure of free recall performance (viz., the number of items recalled) provides a reasonably good estimate of asymptotic recall if a relatively long recall period is used (which is rare), but the effect of experimental manipulations on the rate of approach to asymptote cannot be determined without timing when recall responses occur. The research reviewed herein suggests that the rate of approach to asymptote may offer an estimate of the breadth of search through long-term memory. The search in question, unlike most ofthose investigated in the memory literature, is unique in that it requires minutes rather than milliseconds to complete.When subjects attempt to generate items from a semantic category or to recall a recently presented list of words, they do not complete the task in an instant. Instead, their performance is almost invariably characterized by intermittent successes occurring over an extended period of time. In spite of this interesting fact, memory researchers have exhibited an overwhelming preference for recording which (or how many) items are recalled during some brief period of time, regardless of the speed with which those items have been retrieved. Does the time course of free recall offer any useful information about the nature of retrieval? Because this subject is an old one that commands little attention today, one might assume that the answer is no. However, a review of the extant literature, limited as it is, suggests otherwise.Exactly what can be learned that is not already known by studying the dynamics of free recall? First, the studies that have tracked the time course of recall usually reveal that subjects continue to make progress far beyond the 1-or 2-min recall period typically provided. Indeed, Roediger and Thorpe (1978)-to take one example that will be considered in detail later-reported that recall on an episodic memory task continued to increase more than 20 min into the recall period. Moreover, a clear difference in the level of recall between two conditions (easily named pictures vs. words) became evident only after several minutes had elapsed. Had these authors used the standard brief recall period, they might have mistakenly concluded that the two conditions produced equal levels of performance. How often are incorrect conclusions arrived at because the recall period is too brief? The answer is Correspondence concerning this article should be sent to John Wixted, Department of Psychology-OfOs, University of California, San Diego, La Jolla, CA 92093. 89 unknown because most researchers simply ignore the potential problem.Second, most of the literature reviewed below suggests that the time course of free recall, like reaction time in the Sternber...