Developmental trends in haptic and visual free classifications: influence of stimulus structure and exploration on decisional processes.

This research explores whether the differences observed between the development of visual and haptic free classifications (Berger & Hatwell, 1995) depend from the nature of the information available at different levels of processing. Two experiments are reported, in which subjects were presented with a free classification task using tetrads in the haptic modality (Experiment 1) or in the visual modality (Experiment 2). The type of response elicited (dimensional vs global) was studied as a function of the nature of exploration in Experiment 1 and as a function of the stimulus components' presentation in Experiment 2. Results showed that both the characteristics of exploration and the presentation of the dimensions tended to modify the type to response elicited. The observed modifications, however, were shown to be of different nature in children and in adults. These results were discussed with reference to the development of the valued classification criteria, which could depend on low-level information in young children and on higher-level information in adults.