Teacher research--often called "action research"--is an intentional and systematic inquiry into one's own classroom practice with the goal of improved student learning (Cochran-Smith and Lytle 1993). In this article, the authors present a teacher research project undertaken to improve student understanding of the gas laws in a high school chemistry class. It addresses both the product of this teacher research project--insights into the teaching of gas laws--and the process and potential power of this approach. (Contains 7 figures.)