This article analyzes collaboration in a computer-supported learning environment based on the professional practices of mediation and dispute resolution. In so doing, it explores the nature of collaborative learning in a setting marked by competition as much as cooperation. Interviews with students suggest that the processes of collaborative learning in this competitive environment were fundamentally similar to collaborative learning processes observed in more cooperative contexts (Hutchins, 1995). Individual learners assumed roles that mapped to important elements of the conceptual domain. Learners developed understanding through feedback on their own role from peers, and by observing their peers enact roles that represented alternative facets of the domain under study. The cognitive processes of computer-supported collaborative learning thus appear similar whether students are working toward more shared or more conflicting goals. (Contains 1 figure and 6 notes.)