A preliminary report on the California Achievement Tests (CAT) performance of students attending the Public School Academy (PSA) in Minneapolis (Minnesota) in 1988-89 is presented. The performance of students in grades 2-4 on the CAT reading comprehension and mathematics computation subtests and the performance of students in grade 4 on the mathematics concepts and applications subtest are summarized. Only students with both pretest and posttest scores were included in the analysis. The following findings are reported: (1) students scored at a wide range of levels on the fall 1988 reading comprehension test; (2) overall, students showed improvement in reading comprehension, with third graders showing the most improvement; (3) 61 percent of the students gained at least 10 grade-equivalent months in reading comprehension, with 57 percent of the third graders gaining at least 30 grade-equivalent months; (4) the amount of change in reading comprehension levels between fall and spring was not always directly related to the student's initial achievement levels; (5) all students showed improvement in math computation; (6) 76 percent of the students gained 10 grade-equivalent months in math computation; (7) fourth graders made an average gain of 10 grade-equivalent months in math concepts; and (8) the PSA did not achieve its goal that 75 percent of its students would gain at least 14 grade-equivalent months on the CAT. Statistical data are included on eight tables. (FMW)