Instructionally, schools tend to be "weakly normed" organizational systems in which teachers bring relatively little pressure upon each other to change and/or improve their classroom performance. Because teachers tolerate a wide range of behavior among their colleagues and are reluctant to offer criticism of each other, those responsibile for improving instruction (principals, helping teachers, and supervisors) are left in an organizationally untenable position. Bereft of organizational support in their work, supervisors are left with two broad strategies for accomplishing their organizational mission. One unlikely strategy is to attempt to change the overall organizational/normative character of the schools. A more plausible strategy is to take schools as they are on the twin assumptions that teaching is a highly personal and idiosyncratic activity and that teachers want to improve their instruction. According to this second approach, the most effective supervisor would then be that person who gains the personal confidence of as many teachers as possible--offering advice only by invitation--and thereby establishes a reputation for being a helpful, good listener with something to offer that teachers perceive to be of value. (JBM)