A model is developed which relates an index of school performance to management policy under a variety of environmental conditions. The process of education is defined by the qualitative concept that education is a process of communication. In the model development, the assumed relationships among the variables (factors controllable by management and factors determined largely by the nonschool environment) are first listed and then a mathematical analog to the statements is developed. At the present stage of development the model relates changes in achievement test scores (on a school by school basis) to pertinent resource input factors. Data from a sample of schools is used to estimate parameters and to test the model's ability to predict performance from management policy. The results of the empirical work are presented and practical implications for further research and for school system administrators are discussed. (HW)