Masking disagreements hides the individual struggles to practice wisely, and so removes an opportunity for learning. Politely refraining from critique and challenge, teachers have no forum for debating and improving their understandings. To the extent that teaching remains a smorgasbord of alternatives with no real sense of community, there is no basis for comparing or choosing from among alternatives, no basis for real and helpful debate. This lack impedes the capacity to grow. The individual teachers .
Teachers also bring different pedagogical understandings and expertise to the group discussions.
By drawing on each individual's private understandings, which represent these different degrees of pedagogical and disciplinary expertise, the collective understanding of the group is thus advanced. Together, participants developed principles of instructional conversations for elementary classrooms as they engaged in instructional conversations themselves. Their staff development team brought research-based ideas about learning and instructional practices to the task of developing and examining practical arguments. Teachers provided knowledge about their students, the particular settings in which they taught, and their own teaching practice. Although these three projects differed in their goals, they all illustrate the bringing together of teachers and university-based researchers or staff developers into new forms of discourse communities focused on teaching and learning.