This study investigated how different types of computer-mediated communication (CMC) such as asynchronous forums, synchronous forums and e-mail were used to support an alternative approach to initial teacher education that relied on the formation of a knowledge-building community (KBC). The KBC involves students working in small and large groups to solve `real world' problems, and in the process develop skills of negotiation, communication, and collaboration. Emphasis is placed on authentic problems that are linked to a school context. The findings showed that the students preferred to use the forum available to all participants. Also they used the forums in many different ways, in addition to those intended by the authors. Further, many students made use of other modes of CMC such as e-mail and synchronous forums downloaded from the web. We also found that many of the skills we used in mediating face-to-face discussion could be transferred to the on-line situation. Keywords Comp...