Goldstone, R. L., & Kersten, A. (2003). Concepts and Categories. In A. F. Healy & R. W. Proctor (Eds.) Comprehensive handbook of psychology, Volume 4: Experimental psychology. (pp. 591-621). New York: Wiley.
Issues related to concepts and categorization are nearly ubiquitous in psychology because of peoples natural tendency to perceive a thing AS something. Zen meditation practices may or may not succeed in allowing a person to grasp the object itself rather than the labels and associations it evokes. In either case, the difficulty of this pursuit affirms the powerful impulse that we have to interpret our world. This act of interpretation, an act of seeing something as X rather than simply seeing it (Wittgenstein, 1953), is fundamentally an act of categorization.
The attraction of research on concepts is that an extremely wide variety of cognitive acts can be understood as categorizations. Identifying the person sitting across from you at the breakfast table involves categorizing something as your spouse. Diagnosing the cause of someones illness involves a disease categorization. Interpreting a painting as a Picasso, an artifact as Mayan, a geometry as Non-Euclidean, a fugue as baroque, a conversationalist as charming, a wine as a Bordeaux, and a government as socialist are categorizations at various levels of abstraction. The typically unspoken assumption of research on concepts is that these cognitive acts have something in common. That is, there are principles that explain many or all acts of categorization. This assumption is controversial (see Medin, Lynch, & Solomon, 2000), but is perhaps justified by its potential pay-off. If there are common principles governing concepts in their diverse manifestations, then discovering these principles would have a tremendous benefit, for we would not only acquire an understanding of how people identify faces, recognize letters, treat diseases, or form categories in a specialized domain. We would also have a unified understanding of all of these phenomena as examples of a generic process of concept formation.