This technical report describes the procedures followed in developing the tests used in the California Assessment Program, the underlying principles of the program, the statistical characteristics of the tests, and the evidence that has been accumulated relating to the validity and reliability of the tests. The report also presents complete descriptions of the process of computing the scores and comparison score bands reported on the 1974-75 and 1975-76 reports for the schools and school districts in California. Background factors included: Previous test scores, socioeconomic index, percent bilingual, percent in Aid to Families with Dependent Children, parental education, and student mobility. Explanations are given for the statistical procedures that were used. The appendices contain correlation matrices and norms tables. (Author/CTM)