New Mexico school districts participated in the 1980-81 Statewide Testing Program at grades 5, 8, and 11, to measure achievement in basic skills using the Comprehensive Tests of Basic Skills. Longitudinal comparisons by years (1979, 1980, and 1981) and grade level, and item analyses assessing students' performance in meeting instructional objectives and content are shown in reading, language, mathematics, reference skills, science, and social studies. The test results indicate national percentile ranks, the percentage of students who scored above the 50th percentile, and a distribution of the percentage of students who scored within each of four national quartiles. In comparison with 1980 and 1979, fifth and eighth grade students' national percentile ranks (NPR) improved or stabilized in all test areas. Eleventh grade NPR's stabilized in all areas over the 3-year period. The appendices contain statewide summary data for comparison with local school district item analysis data, sample work graphs to analyze performance, and a description of the optional Short Form Test of Academic Aptitude. (CM)