Standardized tests of writing ability have individual and shared limitations and deficiencies that should be acknowledged by test designers and users. Most institutions use the portions of standardized tests that test ability to proofread and edit, but they do not use the optional essay sections that actually require students to write. To assure validity of a particular test requires item analysis by the department considering using it. An objective test of the student's mastery of standard, edited English does not test equally important abilities to choose a topic, evolve a thesis statement, and actually write a unified, coherent essay. Some teachers will not accept objective tests, insisting instead on writing samples. Other educators claim that essay tests lack reliability and do not correlate with objective test scores and course grades. Work by the Educational Testing Service and College Entrance Examination Board researchers shows how these problems can be overcome. College English departments should conduct score gains studies to give credibility to claims of content validity. Since testing services often do not or cannot give enough information on item analysis, score gains, and correlation in informational booklets, and since individual departments differ from each other, every English department must correlate the composition grades and test scores of its students. (JL)