Assessment data are presented from a representative sample of California public school students in grades 4 through 12 in 115 school districts as of December, 1986. The sample represents 5% of the state's enrollment in grades 4 through 12. Students were tested in reading comprehension, writing, and computation. In grade 12, 9,250 students took one or more of the proficiency tests, and about 20% of them failed one or more tests. It is estimated that, overall, 71% of the students assessed in grade 12 will graduate. A total of 29,775 students in grades 10 and 11 took one or more proficiency tests. Half of these students failed one or more tests. A total of 37,604 students in grades 7 through 9 were tested, and 53% failed one or more tests. A total of 27,149 students in grades 4 through 6 took the tests, and about 37% failed one or more. Districts design and administer their testing programs and establish their own pass/fail criteria. The results reflect this diversity of policies throughout the state. Twelve tables and seven charts present study information. The cover letter and survey instrument sent to school districts, and a list of the responding school districts are appended. (SLD)