This revised manual for the General Aptitude Test Battery (GATB) discusses: (1) historical development; (2) item analysis; (3) factor analysis; (4) physical format; (5) general working population norms (ages 18-54); (6) intercorrelations of raw GATB test scores and of GATB aptitude scores; (7) development of norms for specific occupations (tables present data for various GATB validity studies on 446 occupations defined by the Dictionary of Occupational Titles); (8) development of norms for specific occupations; (9) validity of norms for specific occupations; (10) development of Occupational Aptitude Pattern Structure; (11) validity of Occupational Aptitude Pattern norms; (12) relationship of aptitudes to college success; (13) effectiveness of tests in selection and counseling; (14) correlations with 40 other standardized tests; (15) reliability and effects of practice; (16) effect of training on scores; (17) effect of sex, minority group status, and cultural exposure on scores; (18) effect of aging on scores; (19) effect of disabilities on scores; (20) 9th and 10th grade norms; (21) use of the GATB with the disadvantaged; (22) use of test results; and (23) a 706-item bibliography. (CP)