A new role for computer-mediated communication in engaging teacher learning within informal professional communities

Computer-mediated communication (CMC) implementations, in particular among teachers, have not lived up to public expectations. This study examines some reasons for this and outlines a conceptual and methodological framework for characterizing the engagement of experienced and novice teachers in informal network-based professional learning communities. I postulate sustainability to positively correlate with what I term "CMC engagement." This study addresses three key research questions: (1) What properties constitute CMC engagement in professional learning e-communities? (2) Why do some CMC groups sustain themselves, whereas others do not? (3) How might the communicative structures of network-based CMC enhance or constrain the development of their e-communities, and in turn, pertain to CMC engagement? I argue that both the dialogicality of utterances (Bakhtin, 1986) and the use of texts as "thinking device[s]" for generating new meanings (Lotman, 1990; Wertsch, 1991) are essential for engaging practitioners' professional life. Using both qualitative and quantitative methods, longitudinal discursive data from public teacher email lists are subject to microgenetic, discourse, and ethnographic analyses, resulting in a novel taxonomy of e-communities and a characterization of CMC engagement. The findings provide a new formulation for sustainable learning in CMC-based professional teaching and learning environments, in both informal and formal settings.