The paper presented refers to the functions and effects of educational offices in the public administration (ministry of education) of the Swiss cantons of Bern and Zürich that were established at the beginning of the seventies. These offices intended to combine scientific information with central planning as a new mode of educational policy making. At this time, their focus was a consequence of educational expansion, mainly on the design of a new structure for the lower secondary school level. Establishing planning offices was perceived as a prerequisite of school innovation. However, scientific information had to contend with political contradictions: democratising the school system on one hand, and conserving social status on the other. Burdened by this conflict, the planning of school innovation was only able to operate securely according to political rationality. Policy making in education has to take into account that scientific information is bound to different political rationales and operating procedures.