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 forums available to all participants. Also they used the forums in a variety of 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. Findings also indicated that many of the skills used in mediating face-to-face discussion could be transferred to the on-line situation. (Contains 30 references.) (Author/RS)