During the 1979-80 school year, California public school students in grades 3, 6 and 12 were tested in the basic skills of reading, written expression, and mathematics. Complete statewide results of this California Assessment Program (CAP) are presented, including the following features that have become standard: (1) detailed findings including those of specific skill areas within each major area, and the skill area findings for mathematics reported separately for boys and girls on the basis of socioeconomic level; (2) national comparisons; (3) expert interpretations of the results by identifying skill areas of impressive student performance and those that need attention; (4) test results comparable to those of previous years; (5) subgroup analyses; (6) correlates of achievement focusing on the amount of time students spend watching television, reading, and doing homework. Two important changes to the CAP were related to grade 3 and included a new test of written language and mathematics, as well as a new scaled score reporting system which allows for comparisons of scores from year to year. Two reasons for revising the CAP included enhancing its relevancy and breadth, and using the matrix sampling technique to reduce the amount of testing time.(RL)