The literature on instructional supervision pervasively argues that its manifest purpose is to improve instruction. However, the literature is seriously deficient in proposing any well-articulated theory of supervision, and, consequently, both the conceptual and operational bases for executing supervision's function are in dispute. Hence the current body of literature is marked by a diversity of perspectives. The present paper is a first attempt at a comparative analysis of a representative sample of perspectives. Seven perspectives on instructional supervision--administrative, clinical, counseling, curriculum, motivation, human relations, and microteaching--are analyzed on the basis of 11 selected variables--conception of teaching, basic underlying assumption, focus, role and function, structure, conceptual base, specialized supervisor training, intended outcomes, organizational position of the supervisor, power base of supervisor, and the nature of the supervisor-teacher relationship. The major results of the analysis indicate high conceptual and operational variability among the models, substantial overlap among conceptually distinct perspectives, variability in scope of supervisory functions, variability in compatibility with existing organizational realities, and variability in internal consistency. (Author)