The development of a common instructional language used by teachers and administrators to describe their beliefs about student learning and to coach other teachers can be an important factor in the adoption of instructional change. This investigation of the relationship of language, belief, and practice is the culmination of a historical analysis of the school reforms of mastery learning and outcomes-driven education in the Johnson City Central School District, New York. The paper reviews conceptual models of individual behavior and change within organizations, the characteristics of social learning, and the relationship between thought and language. It argues that an instructional language based upon educational research and a commonly shared mission and rooted in the local culture will increase teacher efficacy for both the coaching teacher and the teacher being coached. A common language will also increase the efficiency of communication within the organization. Thus, the tolerance for interdependence between different levels in the system will increase, which will enhance system-wide adoption of instructional change. (Author/AMH)