Traditionally, human cognition has been seen as existing solely "inside" a person's head, and studies on cognition have by and large disregarded the social, physical, and artifactual surroundings in which cognition takes place. Recently, however, research in cognition and in such fields as anthropology and cultural psychology has compelled us to reexamine our preconceptions. The essays in this volume propose that a clearer understanding of human cognition would be achieved if studies were based on the concept that cognition is distributed among individuals, that knowledge is socially constructed through collaborative efforts to achieve shared objectives in cultural surroundings, and that information is processed between individuals and the tools and artifacts provided by culture. Although the phenomenon of distributed cognitions is a wide-ranging one with provocative consequences for theories of the mind, learning, and education, it has not yet been thoroughly examined. When "distributed cognitions" are the units of analysis for research and theory construction about reasoning and learning, several questions arise: What exactly is distributed and how does it become distributed? Are all cognitions always distributed? How do the distributed qualities of the mind relate to the ones that are still "inside" it? What constraints govern the dynamics of such distribution? In addressing these questions, this volume reveals their importance for such educational issues as the cultivation of mental skills, the acquisition of knowledge, and the role of social interaction and intelligent tools in the learning process