Influences of retrieval processes on the spacing effect in free recall

Tested a 2-process theory of the spacing effect in free recall in 4 experiments with a total of 216 college students and paid Ss. The 1st process, differential organization, produces a positive correlation between the spacing of the presentations of repeated words and the number of different retrieval routes that can provide access to the words. The retrieval process interacts with the differential organization to control performance. If the cues used to retrieve the words provide approximately equal access to all retrieval routes, then the function relating spacing to recall will increase monotonically. If only selected retrieval routes are used, then the spacing function will be nonmonotonic. Results supporting this theory are that (a) the monotonic spacing function was most robust when Ss studied the list using an organizational strategy, (b) cuing and directing retrieval with input words resulted in a nonmonotonic effect of spacing when Ss had used an organizational strategy, and (c) directing retrieval by instructions about the order of recall resulted in a nonmonotonic effect of spacing. (22 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).