This paper develops and estimates a model of the educational process. Most researchers have relied on a single equation, educational production function, which is an unrealistic formulation. A pupil's achievement, motivation, expectations, self-concept, and his perceived parents' and teachers' expectations are determined jointly, not independently. For this reason, this research models the educational process by a set of simultaneous equasions. Utilizing a sample of over 16,000 twelfth grade pupils from the Equality of Educational Opportunity Survey combined with information on their teachers and principals, two stage least squares are used to estimate the parameters of a linear model. The sign and significance of the regression coefficients provide important guidelines for the manipulation of policy variables such as the teacher-pupil ratio, school facilities, and racial composition. (RC)