Extended recency effect extended: blocking, presentation mode, and retention interval.

The effect of blocking of stimulus items on the free recall of EMR adolescents was examined. In Experiment 1 a multitrial free-recall list of 15 pictures was presented either simultaneously in groups of 3, or sequentially, one at a time. Consistent ordering was used in both conditions, so that on each trial, each item in each set of 3 pictures was presented contiguously with the other 2 items from that set. In addition, recall came immediately or after a filled or unfilled delay of 24.5 seconds. Results showed that simultaneous presentation led to higher recall, subjective organization, and clustering than did sequential presentation, but analysis of serial-position curves showed a much reduced extended recency effect in comparison with previous studies. Experiment 2 was designed to determine whether the cause of the reduced extended recency was the use of pictures rather than words as stimuli. Stimuli were presented either as pictures, as pictures with auditory labels, or as words with auditory labels, with both simultaneous and consistent ordering for all conditions. Results indicated a strong extended recency effect for all groups, eliminating presentation mode as a causal factor in the data of Experiment 1. We concluded that blocking leads to increased organization and recall over a variety of presentation modes, rates, and block sizes.

Facilitation of class-inclusion performance in mildly retarded adolescents: feedback and strategy training.

Two experiments were conducted to explore the feasibility of training mildly retarded adolescents to solve class-inclusion problems. In Experiment 1, the effects of training consisting primarily of feedback were investigated. In Experiment 2, training with feedback alone vs. training with feedback plus a counting strategy was compared. Both experiments assessed the generality of training effects to specific training and/or posttest formats. Results suggested that training was generally effective in improving performance with untrained class-inclusion problems on immediate and delayed posttests. Feedback training with pictorial stimuli appeared to be effective regardless of posttest format. The effects of the other training method/format combinations varied according to posttest format.

Sentence mediation and stimulus blocking in free recall.

In a two-phasing training study, EMR adolescents were initially provided with sentences linking each pair of 2 words in a 20-word list to be free recalled. In a second phase, subjects were required to create and verbalize their own sentences. This sentence-mediation condition was compared with (a) one in which items were presented in the same fixed pairs from trial-to-trial, but without sentences and (b) a group that received items in changing pairs. Results indicated superiority of both sentence-mediation and fixed-pairs treatments in comparison to the changing-pairs condition on both correct recall and subjective organization. Sentences did not facilitate recall more than did consistent ordering. The results were discussed in the context of the growing evidence that providing input structure can remediate organization deficits in retarded persons.