This volume features the complete text of the material presented at the Twenty-Fifth 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 theme of this year's conference was the social, cultural, and contextual elements of cognition, including topics on collaboration, cultural learning, distributed cognition, and interaction.