This article reports on an action research project in which two New Zealand classroom teachers worked with a university researcher to investigate the effects of their knowledge, thinking, and beliefs on the ways in which they mediated students' learning in teacher-student interactions. Working in a small community of practice over a two-year period, the group carried out four cycles of action research. They gathered information through semi-structured interviews and classroom observations, and engaged in professional reading, reflection, and discussion. Initially the group found discrepancies between the teachers' espoused theories and their theories-in-use. Implicit beliefs and routinised behaviours were found to have a detrimental influence on the nature of the teachers' interactions with students. Through examination of their own practice and participation in reflective professional development, the teachers were able to make incremental changes and improvements in their interactions with students. (Contains 4 tables.)