Proceedings of the Annual Meeting of the Cognitive Science Society

Previous studies of gradedness have failed to distinguish between the issues of typicality and category membership. Thus, data which have been taken to demonstrate that membership is a matter of degree may only demonstrate that typicality is graded. The present paper reports the results of two studies that attempt to overcome limitations of past methods. In the first study, subjects were asked to rate both typicality and category membership for the same stimuli as a way of distinguishing the two questions. A second study was based on the notion that there may be no definitive answer to questions about membership in graded categories. Thus, disagreements about membership in all-or-none and graded categories may have different qualities Stimuli included animal and artifact categories as well as animals that had undergone different kinds of transformations. Results from both studies suggest some support for claims that membership in animal and artifact categories is graded.