Parts and the basic level in natural categories and artificial stimuli: Comments on Murphy (1991)

Abstract

Natural taxonomies consist of categories that vary in level of abstraction. Categories at the basic level, such as chair and apple, arepreferred in a broad range of situations (Rosch, Mervis, Gray, Johnson, & Boyes-Braem, 1976). Several studies have revealed qualitative differences between the basic level and other levels. For example, Tversky and Hemenway (1984) presented evidence that parts proliferate at the basic level, they proposed that parts link the appearance of category members with their functions. Although not taking issue with these findings, Murphy (1991) investigated whetherparts are necessary or sufficient for a basic level In an attempt to demonstrate that parts are not necessary, Murphy used artificial stimuli that did not capture the essential features of natural taxonomiea These discrepancies preclude any conclusions based on his studies. Murphy's data also do not support his claim that parts are not sufficient for a basic level Finally, ii is unlikely that pur8uing questions of necessity or sufficiency will produce insights into human categorization. © 1991 Psychonomic Society, Inc.