This is a preliminary report of a project which has as its goal the construction of a mathematical model representing the interrelationships among certain categories of phenomena of the secondary school. These phenomena are classified as being either administratively uncontrollable input, administratively controllable input, or output characteristics of the system. The report is divided into two major sections. The first section includes preliminary multiple regression analysis of data from a sample of 100 California high schools collected by the Western Association of Schools and Colleges. This analysis provides an understanding of basic relationships to be anticipated in future applications of the model. The second section provides an overview of the expectations of the second phase of the project and summarizes the requirements for a full-scale study. An 87-page appendix contains tables illustrating the data collected for the study. (Author/JH)