In the past decade, teacher leadership has emerged as a key strategy for improving the quality of education in U.S. schools. Major foundations, federal education programs, and professional organizations are providing significant support for teacher leadership as a key strategy for improving the quality of education in U.S. schools. Teachers in U.S. schools have a variety of roles and responsibilities in addition to their primary responsibility of teaching in classrooms. While teacher classroom effectiveness has been the focus of extensive research, the roles of teachers as leaders in their schools, districts, and professional associations have been the subject of less research and analysis. The research design for this study of teacher leadership takes a broad view of the roles of teachers in their school and their profession. The study design follows from research-based constructs of the relationship of teacher leadership to education quality in K12 education.