Abstract

This study was planned to improve the same-different categorization task(Lee, 1996) by modifying several procedural problems of it, and to investigate, by manipulating factors such as learning experiences or stimulus types, whether the task could reflect the effects of rules and similarities on categorization. Experiment 1 examined relative effects of rule and similarity on categorization by changing learning experiences, the results showed that learning experiences had an effect on rule effects only. In Experiment 2, the same results as that of experiment 1 were found in the high cohesive condition, but a trade off between rule effect and similarity effect was found in the low cohesive condition. In Experiment 3, two stimulus were presented two stimulus concurrently or successively to investigate the extent the presentation procedure of the same-different categorization task had any relation to similarity effects. There was no statistically significant effect of learning experiences in the concurrent presentation condition, but a trade off between similarity effect and rule effect was found in the successive presentation condition. These results suggest that categorization processes cannot be explained by rule or similarity alone, and that the same-different categorization task can be regarded as a promising task for analyzing relative effects of rule and similarity on categorization.