Responds to four commentaries on the article by Jones and Smith in this issue. Suggests that the comments derive from the possibility that stable concepts might not exist and from the difficulty of imagining what cognition could be without represented concepts. Discusses traditional approaches to stability and variability, and considers what…

Reviews current research on children's concepts and categories that reflects a growing consensus that nonperceptual knowledge is central to concepts and determines category membership, whereas perceptual knowledge is peripheral in concepts and only a rough guide to category membership. Argues that there is no compelling basis in theory or in data…

Comments on the article by Jones and Smith in this issue. Responds to the theses that perceptual information is as much at the core of concepts as is nonperceptual information and that concepts are not represented as such but are computed on-line when needed. Presents a view of the relationship between perception and conceptual knowledge…

Comments on the article by Jones and Smith in this issue. Describes a program of research that demonstrates the important influence of perception on the structure of concepts. Proposes that both perceptual and nonperceptual information are important to conceptual structure throughout the continuum of knowledge acquisition and that perception is a…

Comments on the article by Jones and Smith in this issue. Outlines different perspectives from which the issue of conceptual development is approached, elaborating on the functions concepts serve and variations in those functions. Notes points of agreement with the perceptual knowledge view and offers comments on the research supporting the…

This commentary on the article by Jones and Smith in this issue examines whether coherent conceptual cores exist in long-term memory; abstract propositions constitute conceptual cores; concepts in long-term memory control behavior; and the primary purpose of developing and using concepts is to taxonomize the environment. (TJQ)

Reviews "An Odyssey in Learning and Perception" (E. J. Gibson), a volume of collected works that present a first-hand account of many advances in psychology over the past 60 years. A discussion of the two basic questions that capture the essence of Gibson's research, "What is learned" and "What is information" is…

Tested children with apparatus that dropped balls through clear or opaque interwoven tubes. Found that older children could solve configurations with greater number of tubes than younger children. Success with clear tubes did not transfer to opaque tubes. Significantly, errors were consistently directed to location directly below ball's last seen…