Many educational researchers, teachers, and policy makers now believe that students learn through participation in social interaction. Teamwork involves two or more people working together on a task. Collaborative learning or cooperative learning involves students working as a team on some kind of learning task. The Web supports collaborative activiites across a spectrum of possibilities, from writing a paper or book together, to sharing the work on large scale science projects. The power of the Web is in its support for distributed work that can be shared through the medium of the Internet.