The relationships between selected subtests from the Armed Services Vocational Aptitude Battery (ASVAB) and corresponding subtests administered as computerized adaptive tests (CAT) were investigated using Marine recruits as subjects. Three adaptive sub tests were shown to correlate as well with ASVAB as did a second administration of ASVAB, even though the CAT subtests contained only half the number of items. Factor analysis showed the CAT subtests to load on the same factors as the corresponding ASVAB subtests, indicating that the same abilities were being measured. The preenlistment Armed Forces Qualifica tion Test (AFQT) composite scores were predicted as well from the CAT subtest scores as from the retest ASVAB subtest scores, even though the CAT con tained only three of the four AFQT subtests. It is con cluded that CAT can achieve the same measurement precision as a conventional test, with half the number of items.