Typically teachers experience professional development as something that is presented with minimal opportunity for teacher choice and decision-making. Yet when teachers have the opportunity to go beyond the conventional discussion of "what works" and instead pursue questions about their classroom practices and the factors that shape it, teachers experience a new source of motivation and transform the way in which they view themselves and their work.

This qualitative research study explores teacher research as a meaningful form of professional development. It is centered on eight middle school mathematics teachers who reflect about their participation in a mathematical discourse project and their individual efforts of conducting teacher research. Two broad questions frame this study: Why do teachers choose to come together for professional development? What does it mean to do teacher research as professional development? In order to pursue this dissertation topic, I used focus-group and individual interviews to gather data.

Three significant findings are related to reflective practice, collaborative learning, and teacher identity. This study shows that when teachers reflect within a supportive community on their beliefs and on their practices as revealed by videotape, the comparison can serve as a catalyst for classroom research. The teacher-research experience provided a means by which the teachers reimaged themselves as knowers and interpreters of their classroom practices. This study has implications for administrators, mathematics supervisors, and teachers who are interested in understanding issues related to teacher research and professional development.