This volume features the complete text of the material presented at the Twenty-Third Annual Conference of the Cognitive Science Society. As in previous years, the symposium included an interesting mixture of papers on many topics from researchers with diverse backgrounds and different goals, presenting a multifaceted view of cognitive science. This volume includes all papers, posters, and summaries of symposia presented at the leading conference that brings cognitive scientists together. The 2001 Cognitive Science meeting dealt with issues of representing and modeling cognitive processes, as they appeal to scholars in all subdisciplines that comprise cognitive science: psychology, computer science, neuroscience, linguistics, and philosophy.