ABSTRACT
There is a very strong folklore among mathematics and science educators about the difficulties that teachers experience as they shift from conventional forms of teaching to teaching for understanding (see, e.g., Ball & Rundquist, 1993). Using data that we collected in a larger study of six research sites (Gamoran et al., 2003), we developed three interrelated hypotheses about the role of uncertainty in this process: (a) Uncertainty becomes salient within all facets of teachers' practice as they adopt teaching for understanding. (b) Teachers' professional communities are valuable sites for the management of that uncertainty. (c) New forms of technical knowledge are created as a product of those communities.
