As a starting point, we define CMC in the broadest manner since the term is now used to cover a wide range of tools that are being adapted to a diverse set of learning environments. In this broad definition, CMC refers to any form of interpersonal communication that uses some form of computer technology to transmit, store, annotate, or present information that has been created by one or more participants. Using this definition, CMC tools include email, conferencing, groupware, chat rooms, desktop videoconferencing, and Internet-based audio applications. A good overview of these tools can be found in Woolley's overview article [17]. Collaborative learning, also known as cooperative learning, can be defined as the instructional use of small groups through which students work together to maximize their own and each other's learning. A good initial background to collaborative and cooperative learning can be found at http://www2.emc.maricopa.edu/innovation/CCL/CCL.html. Why should we consider CMC and collaboration as important educational methodologies? Certainly both are being incorporated with increasing frequency in a wide variety of contexts and curricula to improve current practice. On a global scale, these technologies and approaches, often in combination with other tools for distance education, will play an important role in delivering education. This will apply to those out in the work force who will need regular educational experiences and retraining due to job changes that require career shifts throughout life. Even more dramatic are the challenges facing countries dealing with rapid population growth and the need to rapidly increase the educational capacity of already stretched institutions. These pressures are likely to foster the development of instructional systems that are more economical than our current face-to-face models. Technology in general and computer-based systems in particular can play a critical role in addressing these problems.