Professional groups, such as teachers, constitute an important part of civic society. The modes of communication and the workings of such groups make significant contributions to general concepts of citizenship. E-communication has increasingly developed as a mode of discourse among and within professional groups and various concepts of community (viz. Communities of Practice, Communities of Learning) are being used as explanatory models to understand these new forms of discourse. This paper seeks to draw out the defining characteristics of such models in the context of a national forum for e-conferencing - The Learning Schools Programme, a UK-wide forum with around 50,000 participating teachers. The paper, which will include survey and case study material, aims to relate theoretical models to an understanding of what constitutes a 'successful' professional community.