The ACT Assessment is a measure of skills in English, mathematics, reading, and science reasoning necessary for college coursework. This booklet includes four sections designed to help the assessment user. Section 1, "Components of the ACT Assessment," contains general information about the assessment for counselors and college advisors and other staff. Section 2, "ACT Assessment Reports and Data Services," is designed for the high school and college users. Section 3, "Using ACT Assessment Student Data," is also for both high school and college users. In Section 4, "ACT Assessment Participation," the information is mostly for high schools, although colleges might be interested in the material about college testing. The ACT Assessment includes four curriculum-based tests that measure students' educational development in English, mathematics, reading, and science reasoning. The tests are based on the major areas of instruction in U.S. high schools and colleges, so that a student's performance on the test has a direct and obvious relationship to his or her academic development. The Assessment also includes a High School Course/Grade Information questionnaire, an interest inventory, and the Student Profile section. (Contains 6 tables, 16 figures, and 38 references.) (SLD)