The final chapter of this book explores new ways in which teachers' use of technologies in schools may be considered. In particular, the reader is challenged by six propositions regarding the influence of communities of practice on in-service teachers' TPACK enactment: (1) processes of identity development and practice constitute aspects of context in which an individual enacts their TPACK; (2) membership of a communities of practice is more complex than newcomers and old-timers and includes near-peers and liminal members; (3) the enactment of TPACK among teachers in a communities of practice is not always consensual or coherent; and (4) challenges to the assumptions of consensus implicit in concepts such as "joint" enterprise, "mutual" engagement and "shared" repertoire are revealed in communal negotiations involving TPACK enactment and reification. As such, the reification of practice is influenced by professionals' perceptions of power and authority--(5) a communities of practice can have multiple, simultaneous and context-specific joint enterprises which can challenge the relationships between the forms of knowledge underpinning TPACK enactment, and (6) mutual engagement reveals TPACK as knowledge in the making. [For the complete volume, "Digital Technology, Schools and Teachers' Workplace Learning: Policy, Practice and Identity," see ED573988.]