ABSTRACT
This chapter describes an informal definition of the term concept, and discusses several general issues pertaining to concept research. It proposes that the centrality of concept learning in cognition makes it an ideal vehicle for unifying seemingly disparate strands of cognitive research. The chapter discusses four major perspectives on the nature of conceptual representation: namely, concepts as rules, as prototypes, as exemplars, and as structures. It provides an overview of empirical research on concept learning and categorization. The purpose of this overview is to introduce the reader to some of the traditional research methods and representational paradigms employed in the field of concept learning. One of the great theoretical divides in the field of human concept learning comes from the ontological distinction that can be made between ill-defined and well-defined concepts. The chapter examines an important notion known as 'linear separability' that has served as a key experimental constraint for comparing prototype categorization with exemplar categorization.
