According to organizational theory, the administrative structure of schools has an effect on the feasibility and ease of improving their operation. To determine whether schools are better characterized as rational bureaucracies or as loosely coupled systems or whether some schools belong to each model, four dimensions were operationalized (goal consensus, centralization of influence, vertical communication, and rule enforcement) that would receive high scores in a rational bureaucracy. Approximately 1,300 teachers from a random sample of 50 schools drawn from southeastern Pennsylvania were administered questionnaires that collected data concerning the organizational structures of their schools. A series of cluster and discriminant analyses revealed two distinguishable groups of schools, one associated with each model. The results of this research have substantial practical as well as theoretical utility. (MLF)