Differential predictability of preferences and choices

A combined multi-attribute utility and expectancy-value model has repeatedly been found to yield a worse fit to choices than to preference ratings. The present study investigated two possible explanations for this finding. First, people's belief-value structures may change in the choice task as they try to find the best alternative. Second, a difficult choice task may cause the decision maker to use simplifying heuristics. In the first of two experiments, subjective belief-value structures were measured on two occasions separated by about one week. Immediately before the second measurement, different groups of subjects performed a choice task, gave preference ratings, or performed a control task. The results did not support an interpretation of the greater difficulty of predicting choices in terms of changes in belief-value structures. However, the notion of simplifying heuristics received support by the finding that adopting simpler versions of the original model improved the predictions of the choices. In the second experiment, beliefs were measured immediately before or after each of a series of choices or preference ratings. The results indicated that although temporary changes in beliefs may occur, they can hardly provide a full account of the differential predictability of preferences and choices.     

The judgment-choice discrepancy: Noncompatibility or restructuring?

The study examines the relative merits of a noncompatibility and a restructuring explanation of the recurrent empirical finding that a prominent attribute looms larger in choices than in judgments. Pairs of equally attractive options were presented to 72 undergraduates who were assigned to six conditions in which they performed (1) only preference judgments or choices, (2) preference judgments or choices preceded by judgments of attractiveness of attribute levels, or (3) preference judgments or choices accompanied by think-aloud reports. The results replicated the prominence effect for choices, but a prominence effect was also found for preference judgments. In accordance with the restructuring explanation, the think-aloud protocols indicated that options were more often restructured in choices than in preference judgments. However, restructuring could not explain the prominence effect observed for preference judgments. A modified compatibility hypothesis is offered as an alternative explanation.     

Is knowledge base development a necessary and sufficient condition for memory development?

The hypothesis that knowledge base development is an important condition for memory development was tested in two experiments. In Experiment 1 subjects from grades K, 6, and college participated in an incidental learning task where they analyzed words according to one of four featural systems: physical, acoustic, semantic, and imagery. Large developmental differences in recall were found in the imagery and semantic conditions, small differences were observed in the acoustic conditions, and no developmental differences were found in the physical condition. Experiment 2 involved presenting college students and third graders words either from categories highly salient to third graders, e.g., cartoons, games, etc., or from corresponding Battig and Montague categories generated by college students. Free recall and clustering performances showed significant interactions, with third graders superior on the third-grade salient items, and college students superior on Battig and Montague items.     

Spatial interactions of taste stimuli on the human tongue

Two nearby loci on the human tongue were stimulated with solutions representing the four basic taste qualities. The recognition threshold for each test stimulus was measured when a strong concentration of one of the four qualities or water was placed nearby. Decreased sensitivity for the test stimulus resulted when both stimuli were the same quality, with the exception of an enhancement of bitter sensitivity by QHCl. The only effect across qualities was a suppression of citric acid by NaC1. In contrast, classical studies reported across-quality enhancement. Stimulation of two loci on the same half of the tongue and the use of modern psychophysical techniques may explain the differences between these and earlier results.     

Comparisons of three different investigative interview techniques with young children

After viewing a film of a mother hitting her son, a film not seen by the college student interviewers, children were misinformed about a detail (via exposure to a misleading question) as well as explicitly coached to disclose 3 false details. The children were then interviewed by interviewers who had previously learned 1 of 3 different interviewing procedures: the Yuille Step-Wise Interview developed by J. C. Yuille, R. Hunter, R. Joffe, & J. Zapamiuk (1993); a doll play interview developed by Action for Child Protection Inc. (1994); or the Modified Structured Interview developed for this study. The Modified Structured Interview yielded more "where" information and was better at detecting if coaching had occurred. However, the interviewers were not very good at discriminating suggested versus coached versus correct witnessed information. The authors found that the deeper one digs for memories, the more one uncovers incorrect versus correct items. They concluded that although the Modified Structured Interview was superior to the techniques currently in use, cautions are necessary.     

On the relation between object manipulation and stereotypic self-injurious behavior

Results from a number of studies have shown an inverse relationship between stereotypic behavior and object manipulation. The purposes of this study were to determine whether techniques similar to those used previously (prompting and reinforcement) would be effective in increasing object manipulation under both prompted and unprompted conditions, and to ascertain whether increases in object manipulation would result in decreases in stereotypic self-injurious behavior (SIB). Two individuals with developmental disabilities who engaged in SIB maintained by automatic reinforcement participated. Results showed that object manipulation increased from baseline levels when experimenters prompted participants to manipulate leisure items, but that object manipulation was not maintained under unprompted conditions, and rates of SIB stayed within baseline levels. We then attempted to increase object manipulation further by (a) reinforcing object manipulation, (b) blocking SIB while reinforcing manipulation, and (c) preventing SIB by applying protective equipment while reinforcing object manipulation. Reinforcing object manipulation alone did not affect levels of object manipulation. Blocking effectively reduced attempts to engage in SIB for 1 participant but produced no increase in object manipulation. When the 2nd participant was prevented from engaging in SIB through the use of protective equipment, rates of object manipulation increased dramatically but were not maintained when the equipment was removed. These results suggest that stimulation derived from object manipulation, even when supplemented with arbitrary reinforcement, may not compete with stimulation produced by stereotypic SIB; therefore, direct interventions to reduce SIB are required.     

The Development of Attribute Dominance in the Knowledge Base

Two cuing, free-recall studies were conducted to test Bach and Underwood's (1970) hypothesis that acoustic encoding is dominant among second graders and semantic encoding is dominant among sixth graders. When retrieval cues were presented with to-be-remembered items at both input and output (Experiment 1), and when cues were presented only at output (Experiment 2), semantic cues were more efficient in elevating recall than were acoustic cues for both second and sixth graders. When these and other results generally found using recognition, sorting, incidental learning, and free-recall experimental designs are compared, it seems plausible that item presentation and memory-testing formats interact with age, and that these factors account for the different patterns of attribute dominance found in the literature. The knowledge base cannot be understood by focusing on either subject or task analyses, but only by focusing on interactions between subject and task variables as they change over time. The educational implications for young grade-school children are discussed.