Memory for Intratrial Events in Concept Formation

The major purpose of the present experiment was to examine expectations of hypothesis-testing theory, regarding memory for intratrial events, on a concept-identification task. The individual events under investigation were feedback, responses, hypotheses, and stimuli. According to hypothesis-testing theory, subjects should retain information regarding a winning hypothesis from one trial to the next. From introductory psychology 75 subjects participated in the experiment in which they were administered concept-formation problems. All variables were manipulated in a 4 × 4 × 3 within-subject design. Question type, number of intratrial events recalled, and percentage of trials with memory probe were the three factors. One major finding was the number of recall failures for the hypothesis stated on the previous trials. These errors occurred on problems with negative response trials, not with incorrect feedback, which contradicts predictions based on hypothesis-testing models. Over-all, the results support frequency theory over hypothesis-testing models with number of intratrial events and percentage of trials with probe shown to be important variables affecting the accuracy of memory.

Alternative theories of concept identification among older adults

The purpose of the present experiment was to investigate some predictions of hypothesis testing and S-R association (frequency) theories regarding memory for intratrial events on a conjunctive concept-identification task. They have received extensive study with young adults but not with older subjects. The individual events under investigation were feedback, responses, hypotheses, and stimuli. Hypothesis-testing theory requires subjects to retain information concerning the correct hypothesis from one trial to the next whereas frequency does not. 75 subjects (60-70 yr. old) participated in the study. Subjects had difficulty in recalling the correct hypothesis stated on previous trials. These errors occurred on problems with negative response trials, not with incorrect feedback. The results contradict predictions based on hypothesis-testing models but are consistent with frequency theory. Unlike in the studies based on younger adults, present subjects did not recall the hypothesis very well under the conditions in which hypothesis testing was made part of the primary task.