The Armed Services vocational aptitude battery (ASVAB) was developed by a joint-service technical group, using items from the services' previously operational tests. The ASVAB was designed as a potential replacement for the Armed Forces Qualification Test and the separate classification batteries used by each of the services. Thus, the effectiveness of the ASVAB in Navy classification needed to be determined and compared with the basic test battery (BTB). The ASVAB was administered to all recruits at two Naval Training Centers and the men who subsequently attended a Navy Class 'A' school were identified and their BTB scores and school grades obtained. The validities of the ASVAB and BTB tests were investigated within each school and linear-sum correlations were also computed to determine the best combinations of ASVAB tests as possible school selectors. A computerized item selection technique was applied to the tests in each battery. Various item statistics and validities and reliabilities for the shortened tests were obtained for use in evaluating Form 1 of the ASVAB and in development of subsequent forms. Form 1 of the ASVAB was found to be too easy for effective discrimination among Navy students; comparisons of the BTB and ASVAB validities uniformly favored the BTB. (Author/NL)