Legalization here refers to the introduction into the educational system of new legal rules, emanating from outside the routine channels of educational management. It includes general legal rules from legislation, from the courts, or from higher administrative levels. The key to the definition is lack of integration of the new rules with the main rules already constituting the system or the lack of integration of the new channels of control with the old ones. The main argument of this paper is that legalization is a product of the rise of more central (now, national) controls and pressures in a system that is organizationally decentralized. Interventions, in such a system, take the form of specialized rules unintegrated with the rest of the educational system. Such legalization creates a good deal of organizational disorder in the educational system itself, though this is not inevitably to be seen as unsatisfactory. Policy implications and possible future directions for change are discussed. (Author/JM)