This manual contains preliminary information, largely of a technical nature, about the enhanced American College Testing (ACT) Program introduced in October 1989. It focuses primarily on the tests of educational development, the component of the program that has been substantially revised. Although one-third of the ACT Interest Inventory Items has been replaced or revised, the score scale and the interpretation procedures remain unchanged. The manual describes: (1) the enhanced ACT Assessment Program and related services; (2) development procedures for the tests of educational development; (3) norming, scaling, and equating the tests of educational development; and (4) the reliability and validity of the tests of educational development. Twenty-two tables and one figure supplement the discussion. Seventeen references are listed. Appendices provide the ACT Interest Inventory and three concordance tables for composite, English, and mathematics scores. (SLD)