In 1972 the Beaverton, Oregon, School District adopted a diagnostic-prescriptive instructional model as part of its teacher evaluation plan. To help teachers with the construction and analysis of diagnostic tests, the district made three data processing services available: (1) test item analysis, (2) test scoring and summarization, and (3) data storage and retrieval. The test analysis program determined scales of test item difficulty and evaluated the discriminatory power of test items. Options provided by the test scoring service include reporting test results by teaching objectives, comparison of results with mastery criteria, and providing group distributions and other descriptive statistics. The programs were developed on a 20K storage computer with an Opscan 17 scanner as the primary input mechanism. Software was written in Fortran II with a package developed specifically for the Digital Equipment Corporation PDP-8 machine. Evaluation of the effects of the data analysis programs in three years of a 9th grade writing course showed some evidence of student improvement in meeting course objectives. An appendix contains samples of test forms and computer printouts. (KB)