Categorization, Typicality, and Shape Similarity

This work examines the contribution of shape features to subjects' judgments of typicality for visual categories. Shape was found to make a strong contribution to typicality, as evidenced by the strong correlation between results on pictures and those on silhouettes of the same pictures. Also, different measures of the contribution of shape - template overlap, compactness, and number of parts - were shown to capture different aspects of that contribution. As one of the fundamental problems in category research is to determine the features used in categorization (e.g., Medin, 1989), the current work is important because it makes progress on this problem.