[Effect of weight of feature and frequency on recognition of butterfly patterns]

Three experiments are reported which deal with the nature of categorization of natural objects. Stimulus materials were schematic butterfly patterns. Systematic transformations were given to the original pattern to make stimulus instance. In Experiment 1, subjects were given a recognition memory task with recognition ratings. Recognition ratings were found to be related to family resemblance score (FRS: the sum of feature frequency in the category) rather than to transformation or subjective similarity to the original. In Experiment 2, subjects were given the recognition memory task while the FRS was kept constant. Weight of each feature affected recognition ratings differently, when FRS was kept constant. In Experiment 3, subjects were given the same task as in Experiment 2 while the FRS and the component frequency of each feature were kept constant. Again each feature affected recognition ratings differently. These findings suggest that both the frequency and weight of feature itself affect recognition ratings.