To develop a computer system to support cooperative learning among distributed students; developers should consider the foundations of cooperative learning. This article examines the basic elements that make cooperation work and proposes a framework for such computer supported cooperative learning (CSCL) systems. This framework is constituted of five main components to support cooperative group structures, cooperative task structures, cooperative incentive structures, cooperative space structures, and individual accountability structures. To further guarantee successful cooperative learning, the mechanics to teach or reinforce appropriate cooperative skills should be added. This article provides concrete guidelines to the developers of CSCL systems. (Contains 2 figures.)