Teachers engaged in action research are involved in a process that focuses on how they and their students construct and reconstruct learning experiences, thereby extending professionalism and creating additional learning opportunities for students. This paper describes the evolution of an action research project involving an elementary school teacher in collaboration with a school district researcher over a period of about 5 years. Critical incidents are documented and samples of action research activities are used to illustrate progress. Also documented is the impact of the research on classroom practice, lessons learned, and a personal statement about growth and development of the researchers. The role of both participants in this process is described using a group development framework. Five key stages are presented: initiation, dependence, rebellion, cohesion, and interdependence. The paper concludes with a summary chart presenting the many stages of action research, a series of reflective statements, and 67 selected references dealing with teacher effectiveness, teacher-as-researcher, and collaborative action research. (LL)