Teachers enrolled in the master of natural science program for high school science teachers at a large research university must complete a year-long action research study. This account, by the program's action research coordinator, describes both process and outcomes of this research experience from the perspectives of the research coordinator and the teacher–researchers, shedding light on the organizational learning that takes place, and the ways in which the research experience affected individual teacher–researchers. Teachers reported that their action research experience changed them in fundamental ways, providing them with a framework for deepening their understanding of student thinking, challenging their folk wisdom about teaching and learning, building confidence in their abilities and renewing their commitment to teaching as a vocation.