This book summarizes the evaluation by the Committee on the General Aptitude Test Battery (GATB) of the National Research Council of the U.S. Employment Service's use of the GATB. The book serves professional users, policymakers, and students of psychometrics because of its clear and concise review of important issues. (SLD)

Effects of passage and item-scrambling on equipercentile and item-response theory equating were investigated using 2 scrambled versions of the American College Testing Program Assessment for approximately 25,000 examinees. Results indicate that using a base-form conversion table with a scrambled form affects the individual examinee level. (SLD)