A test of resource-allocation explanations of the generation effect

Abstract

Several current theories of the generation effect posit that generated items receive greater encoding resources than do read items in the same list. These theories were tested, by asking subjects to pay special attention to target items embedded in a list of background items. Targets were either read or generated, and received either normal or special attention. Background items were always read. Compared to memory for words in a list of read target and background items, memory for generated targets was enhanced and memory for surrounding read items was suppressed. These results paralleled the effects of the special attention instructions. It was suggested that generation is a controlled process requiring encoding resources that are taken from surrounding read items in a mixed-list design and from relational processing in a between-list design.When people are asked to generate missing material from a to-be-remembered word (e.g., ap_le), performance is enhanced on tests of explicit memory. Currently there are four prominent theories of this "generation effect": the displaced rehearsal hypothesis (Slamecka & Katsaiti, 1987), the inhibition hypothesis (Begg & Snider, 1987), the two-factor theory (Hirshman & Bjork, 1988), and the contextual theory (McDaniel, Waddill, & Einstein, 1988). Although there are many differences among these theories, each theory hypothesizes that generating some items in a list shifts resources away from the processing of intact items in the same list. In the research presented below, this assumption concerning expenditure of encoding resources is evaluated. We begin with a brief review of each theory, focusing on the form of the resourceallocation assumption and the evidence garnered in favor of the assumption. The supporting evidence was found to be open to numerous interpretations, and inconsistencies in the evidence were noted. An experiment that resolved these inconsistencies is then presented; it provided more convincing evidence for the resourceallocation assumption. Slamecka and Katsaiti (1987) provided the most convincing evidence for the encoding resource hypothesis. Subjects were asked to study semantically related word pairs, and comparisons between reading and generating were made both within and between subjects. In the within-subjects design, generated and intact items were mixed in the same list, and a typical generation effect was I with to thank Elliot Hirshman, James Nairne, Constance R. Schmidt, and Norman J. Slamecka for their comments on an earlier report of this research. In addition, I wish to thank Kim Brockdorff, Julie Garver, David Gustavsen, Stephen Johnson, and Vincent Joven for their assistance in data collection and scoring. Requests for reprints should be sent to Stephen R. Schmidt, Department of Psychology, Middle Tennessee State University, Murfreesboro, TN 37132. 93found. However, no generation effect was found in the between-subjects design when one group of subjects read a list of words and a different group generated each word on the to-be-remembered li...

Evaluating the Role of Distinctiveness in the Generation Effect

“…Thus, across all comparisons, increased recall of generated targets was accompanied by a similar decrease in recall of intact background items. This trade-off replicates results reported by Slamecka and Katsaiti (1987) and Schmidt (1990). One interpretation of the trade-off is that generated-items "rob" encoding resources from intact items in the same list (Schmidt, 1990).…”

“…This trade-off replicates results reported by Slamecka and Katsaiti (1987) and Schmidt (1990). One interpretation of the trade-off is that generated-items "rob" encoding resources from intact items in the same list (Schmidt, 1990). Thus, generation leads to increased individual-item processing as a result of increased attention given to generated items.…”

“…A parsimonious explanation of generation effects in both between-and within-subjects designs is that generated items receive increased encoding resources relative to read items. Increased attention may be at the expense of relational processing in between-list designs (Schmidt & Cherry, 1989;Begg et al, 1989), or the processing of intact items in within-list designs (Slamecka & Katsaiti, 1987;Schmidt, 1990).…”

The influence of retrieval on retention

“…Kinoshita (1989, Experiment 4) found that subjects who correctly copied a word originally presented with two underlined, transposed letters performed better on later recognition of the items than did subjects who simply copied correctly spelled words (though this effect did not obtain with free recall as the final test). In addition, Schmidt (1990) found that words for which subjects copied a missing letter (printed to the right of the word) onto the correct blank space embedded in the word were later more likely to be recalled than words that were simply studied in whole form. Another, more likely, possibility is that the generation effect is often due to the combined beneficial effects of retrieval plus the extra processing of the target material demanded by the generation task.…”

The greater memorability of self-generated versus externally presented product information

“…What is critical in producing a generation effect is that the retrieval procedure tap the chosen generation strategy (Nairne, 1988;Nairne & Widner, 1987). Schmidt (1990) has concluded that generation promotes individual item processing at the expense of a more global (e.g., whole-list) processing; thus the effect is most likely when subjects have both the opportunity to read and to generate items in the same list (i.e., the mixed-list format). We believe, and we have assumed, that generation in advertising contexts closely resembles a mixed-list experiment format: Some ads use generation techniques, and some do not.…”