When the Mesa, Arizona Public Schools initiated an ambitious writing instruction program in 1978, two assessments based on student writing samples were developed. The first is based on a ninth grade proficiency test. If the student does not pass the test, high school remediation is provided. After 1987, students must pass this test in order to graduate from high school. The more ambitious assessment is conducted twice per year in grades 1 through 6. Students write a short composition on a prescribed topic. The writing samples are collected, coded, and holistically scored. This evaluation is used primarily to determine student growth and to assess the writing programs. Procedures established to ensure anonymity and reliability in grading the writing samples became tedious to administer. However, in spite of the clerical workload, the writing assessment program persisted. Last year, a computerized scoring process was developed. Each writing sample is read and scored twice, with an overall interrater reliability of .68. Coded scores are recorded on the computer sheet, and fall and spring data are consolidated by the data processing department. The computer system identifies raters who need additional inservice education to improve reliability. Teachers are pleased with the computerized system. (GDC)