Army personnel managers have a continuing need to select, classify and assign to training and jobs large numbers of men who enter the service. The present publication addresses the value of selection and classification testing program in relation to job training success and the suitability of the tests for subgroups of the manpower available to the Army. The various testing programs in the Army's enlisted personnel system are described; the relationships between testing program, training content and method, and utilization on the job are probed; and the methodology is explained by which the validity of the tests is established. Analysis of measures of performance in job training programs and ratings of job performance reveals that training performance is more satisfactory than job ratings for evaluating test effectiveness. How well tests predict performance in training programs and the relation between tests scores and other indexes of success are examined separately for Negroes and whites. (Author)