Encoding variability and organization in free recall

Measures of category clustering and subjective organization are well-established predictors of performance in free recall tasks. The present studies demonstrate that a measure of encoding variability affords equally powerful and independent prediction of free recall performance. They also illustrate an interaction between encoding processes and organizational activity. In Experiments 1 and 2, the independent contributions of organization and encoding variability are demonstrated in categorizable and uncategorizable lists and in subjects whose recall is expected to increase (adults) or decrease (children) as a function of more varied encodings across trials. In Experiment 3, a category labeling procedure is used to demonstrate that the negative relationship between encoding variability and recall can be reversed by inducing adult-like organizational activity in children.     

Semantic processing and organization in free recall

It was hypothesized that both semantic processing and organizational activity are necessary for optimal free recall performance. In a series of three experiments, subjects were presented with a list of randomly selected nouns and were asked to make up a meaningful sentence for each noun. The subjects also rated the difficulty of using each noun. The subjects were instructed to try to remember words that were labeled "remember" words. For words that were labeled "story" words, the subjects were instructed only to make each sentence, using the word, part of an ongoing story which each subject was to make up. A test of retention for all presented words, using retention intervals of both 1 min and 24 h, showed that the story words were always recalled better than were the remember words. However, the amount of sequential organization was the same for both the story and the remember words. Recognition performance was found to be the same for both types of words. In addition, the story words were rated as being more difficult than the remember words. It was concluded that extensive semantic processing without organization is not sufficient for optimal recall.     

Age differences in free recall and subjective organization

Previous studies concerned with subjective organization occurring during free-recall learning have not provided consistent evidence for a hypothesis of organizational deficiency in the elderly. To assess the role of recall conditions in this discrepancy, the free-recall learning of younger and older adults was examined under conditions where the recalled words were either visible or not visible. Also, 5 measures of subjective organization, including measures used in earlier studies, were used to assess the role of measurement factors in producing the inconsistent findings. Younger adults, regardless of recall condition, recalled more words and showed more subjective organization than did the older adults with each of the measures. List length, rather than type of recall trial or measure of subjective organization, seems to be responsible for the conflicting findings obtained by other investigators.     

Spatial organization in the free recall of pictorial stimuli

Thirty-one young adults were presented with a series of visual arrays each containing drawings of objects. Free recall of the objects on each visual array could be organized by the spatial location of the objects or by another type of organization. The other type of organization was different on each array and comprised semantic, shape, colour, size, orientation or phonetic categories. The results showed that free recall could be organized by spatial location or by semantic, shape, colour or size categories. However, only semantic and colour category organization were found to correlate significantly with recall. To account for the correlation results, two distinct general forms of organization are hypothesized.     

Evidence for time-based models of free recall

Is memory temporally organized? According to temporal distinctiveness models of memory, temporally isolated items should be better remembered than temporally crowded items in free recall tasks. Here, we tested this class of model by varying the temporal isolation of items either predictably (Experiment 1) or unpredictably (Experiment 2) in a free recall task. In both experiments, item recall probability increased as a function of the temporal gaps both before and after the item. The results are taken as support for temporal distinctiveness models of memory, in which items are represented and recalled in terms of their positions along a temporal dimension.     

Output organization in the free recall of mildly retarded children

Output organization in multitrial free recall of ‘unrelated’ lists can be quantified using measures of intertrial consistency or subjective clustering, the latter being based on subjective ‘categories’ revealed in a post-recall sort task. It has previously been shown with picture stimuli (Todman 1982) that recall and subjective clustering, but not intertrial consistency, increase with age for nonretarded children. In the present study, mildly mentally retarded children at three age levels were given the same task. Although recall increased with age, there was no age effect on subjective clustering or intertrial consistency. Output organization of the retarded groups was compared with that of nonretarded groups at three age levels. The nonretarded groups comprised previously tested children selected to equate each group with one of the three retarded groups on mean recall. Across all age levels, intertrial consistency was significantly (p < 0.02) higher for retarded groups.     

A functional relation between learning and organization in free recall

It is well known that multitrial free recall is accompanied by increased organization of output over learning trials, even when the order of presentation is randomized. We compared the relation between learning and organization in 30 young and 30 older adults as they learned categorized materials to a criterion of 100% recall. The importance of this age manipulation was that it allowed us to examine, using two groups that differ significantly in their learning ability, whether organization and learning follow the same function. As was expected, older adults showed less organization on any given learning trial. However, when equated for degree of learning, the older adults showed approximately the same level of organization as the young. This finding suggests that the organization-learning relation remains invariant in the face of significant differences in participants’ mnemonic abilities.     

Picture superiority in free recall: The effects of organization and elaboration

A conception of semantic memory structure is presented in which elaboration is considered to vary both between and within items. Pictures and their verbal labels are suggested to activate common abstract memory representations, but these activations will differ in their degree of within-item elaboration. However, pictures and words should show comparable between-item elaboration properties, such as might be revealed by the category-recall relationship and clustering in free recall. Children were presented pictures and words in either a category-recall situation, where between-item elaboration was emphasized, or in a control situation where between-item elaboration was minimized. No differences between pictures and words in either recall or clustering were found in the category-recall task. However, when the same items were presented in the control situation the typical picture superiority effect in free recall was found. The results are interpreted as consistent with a two-factor theory of semantic elaboration, and indicate that these basic properties of memory encoding hold even for young children.     

In search of the M-Gram: The structure of organization in free recall

This paper reviews three major classes of structural models of episodic and semantic memory which have been proposed to describe the organization of permanent memory. Although semantic memory workers have developed methods for obtaining representations of these models from empirical data, students of episodic memory generally have not. A method is presented for extracting representations of memory structure using output order information from a free recall learning task. It is shown that this method can be embedded within each of the three general models of memory structure to produce graphic representations of those structures. These representations may be obtained for individuals or for group data, and in some cases the nature and extent of individual differences in organizational structure can be characterized. A final section of the paper demonstrates the validity of the method using both real and simulated data, shows that the method is sensitive even to small differences in organizational structure, and illustrates the utility of this approach with an analysis of part-whole transfer.     

Developmental changes in word attribute utilization for organization and retrieval in free recall

The development of two distinct but related activities in free recall: organization and retrieval, was examined in relation to the development of memory attributes. Twenty-five words printed on cards were chosen to be cross-classified according to conceptual category and according to acoustic similarity. Second-graders (8 year olds), sixth-graders (12 year olds), and college students (20 year olds) either sorted the stimulus words as they wished, were yoked to another subject's sort, or were instructed to sort the words in a blocked fashion according to one attribute or the other. Age differences in attribute preference for sorting were found, as well as significant interactions between age level and attribute basis for mean recall-within-categories, for cued recall, and for clustering in free recall. The results lend strong support to the theory that attribute dominance does in fact change as a function of age, in terms of both organizational schemes and the role of these schemes for recall, and suggest that psychologists reexamine the present notions of children's organizational skills in recall tasks.     

Associative and categorical hypotheses of organization in the free recall of adults and children

Associative and categorical explanations for the organization children and adults display in free recall were tested. It was expected that young children would show output clustering as a function of associations between individual items within categories rather than relationship to the taxonomy itself. Kindergarten, fourth-grade, and tenth-grade subjects were presented with pictures representing the four factorial combinations of high and low interitem association and high and low category relatedness. Each set of pictures could be divided into four taxonomic categories of six items each. Kindergarteners displayed greater category clustering of highly associated items than weak associates. Older subjects showed sensitivity to both organizational dimensions. These data support a hypothesis that young children cluster in recall as a function of associations while older individuals show organizational flexibility which serves to facilitate greater recall.     

Hypermnesia in free recall and cued recall

In three experiments, categorized lists and both free recall and cued recall tests were used to examine hypermnesia. In Experiment 1, materials were drawn from obvious and nonobvious categories in an attempt to vary the amount of relational processing at encoding. The study materials in Experiment 2 consisted of a long word list that comprised several exemplars from each of a number of common categories. In Experiment 3, a single exemplar was drawn from each of 45 categories. In each experiment, similar magnitudes of hypermnesia were obtained on free and cued recall tests. Examination of the specific items recalled across tests indicated that similar processes underlie the hypermnesic effect for both test conditions. Implications of the results for extant accounts of the hypermnesic effect are discussed. It is concluded that the dynamics of retrieval processes change in a systematic fashion across repeated tests and the retention interval following study and that an adequate account of the nature of these changes in retrieval dynamics is essential to our understanding of hypermnesia and related phenomena.     

A FORTRAN IV program for analyzing higher-order subjective organization units in free recall learning

This paper presents a program for the analysis of subjective organization in free recall and the instructions for the organization of data to use this program. The program is capable of handling lists of up to 40 items, as well as 20 trials of data. In addition, the program provides several types of data tables for unit sizes from 2 to 10 items in length and for three types of sequential ordering criteria.     

Expecting to teach enhances learning and organization of knowledge in free recall of text passages

The present research assessed the potential effects of expecting to teach on learning. In two experiments, participants studied passages either in preparation for a later test or in preparation for teaching the passage to another student who would then be tested. In reality, all participants were tested, and no one actually engaged in teaching. Participants expecting to teach produced more complete and better organized free recall of the passage (Experiment 1) and, in general, correctly answered more questions about the passage than did participants expecting a test (Experiment 1), particularly questions covering main points (Experiment 2), consistent with their having engaged in more effective learning strategies. Instilling an expectation to teach thus seems to be a simple, inexpensive intervention with the potential to increase learning efficiency at home and in the classroom.     

Recall termination in free recall

Although much is known about the dynamics of memory search in the free recall task, relatively little is known about the factors related to recall termination. Reanalyzing individual trial data from 14 prior studies (1,079 participants in 28,015 trials) and defining termination as occurring when a final response is followed by a long nonresponse interval, we observed that termination probability increased throughout the recall period and that retrieval was more likely to terminate following an error than following a correct response. Among errors, termination probability was higher following prior-list intrusions and repetitions than following extralist intrusions. To verify that this pattern of results can be seen in a single study, we report a new experiment in which 80 participants contributed recall data from a total of 9,122 trials. This experiment replicated the pattern observed in the aggregate analysis of the prior studies.     

Organisational processes in free recall

In a free recall task, homogeneity of semantic reference and strong associative connections facilitated the recall after a twenty second filled interval of lists of 18 words. Facilitation in the recall of lists consisting of three sets of six related words when compared with six sets of three related words was also obtained. The organisation present in the recalled sequences is reported using various clustering measures and differences between the measures are indicated and discussed. Difficulties in the use of such measures in evaluating an hypothesis about the relationship between recall and organisation are illustrated and the general theoretical issue of selecting between alternative measures of organisation is considered.