Current reform efforts, focusing on teacher empowerment, are based on the belief that lasting school improvement will occur when teachers become more involved in professional decision-making at the school site. Presented in this document are four conceptually distinct models of teacher involvement in schoolwide decision-making, identified on the basis of a review of previous research as well as field experience; these models are discussed in relation to purpose, the role of teachers and the principal, and potential impact on teacher leadership and empowerment. The first model, the Principals' Advisory Council, has been designed to improve the school's organizational climate through the involvement of a representative group of faculty in the decision-making process. The second model, the Instructional Support Team, is intended to bring about instructional improvement within a specific curricular domain, thus representing significant potential for expanding teacher instructional leadership within the school and empowering teachers within a limited sphere. The third model, the School Improvement Team, increases teachers' professional power, but does not have a direct impact on the classroom. And the fourth model, the Leader Teacher Committee, currently limited to prescriptive proposals and contractual agreements, has been designed to improve educational outcomes for children by increasing use of professional staff expertise and by widening accountability within the school site beyond the principal. (31 references) (KM)