Two questions, two tests
After 1950 the Army asked two separate questions about each recruit. One test answered whether he could be taken at all. The ACB answered where he should go.2,7
What an ACB result looked like
A study at Fort Dix compared the ACB with IBM's own selection tests for a repair course. It printed the scores of one trainee who fell below 100 on every test.5
not reported
Bars hang below the 100 line by how far each score fell short. The GM score was the only one below 100 in the sample; its exact value wasn't reported. The sources don't expand the codes, so we don't either.5
Route a recruit
Drag a test score. The dots show which tests feed each job group's composite, and the bottom row picks the group he'd be routed to.
Illustrative only: the tests, pairings and job groups here are invented to show how composites work. They are not the ACB's actual tests or formulas.
Twenty-seven years in service
The ACB overlapped with the tests on either side of it. It ran alongside the AFQT and was retired once the ASVAB covered both selection and classification.
How the last ACB was validated
The early-1970s rebuild, from data collection to its reported gain.2
References
- [1]U.S. Army Behavioral Science Research Laboratory. Development of improved aptitude area composites for enlisted classification. Technical report (FY1969 work program). DTIC AD0701134.apps.dtic.mil/…/AD0701134.pdf
- [2]U.S. Army Behavior and Systems Research Laboratory. An improved differential Army classification system. Technical research report (FY1971 work program). DTIC AD0748802.apps.dtic.mil/…/AD0748802.pdf
- [3]Evaluation of differential classification tests for the ACB. Technical research note. DTIC AD0621698.apps.dtic.mil/…/AD0621698.pdf
- [4]Report on the Army Qualification Battery (AQB-1). DTIC ADB951280.apps.dtic.mil/…/ADB951280.pdf
- [5]Use of the Army Classification Battery for counseling (Project TRANSITION / IBM study). Research memorandum. DTIC ADA079345.apps.dtic.mil/…/ADA079345.pdf
- [6]Official ASVAB. History of military testing (2023).officialasvab.com
- [7]Defense Manpower Data Center. Military aptitude testing (Technical Report 93-007). DTIC ADA269818.apps.dtic.mil/…/ADA269818.pdf
Related historical tests
The wartime test the ACB succeeded. The AGCT classified about 12 million WWII recruits with essentially one number; the ACB replaced that single score with a set of job-specific aptitude composites.
Where Army mental testing began in 1917–18: a group-administered test of verbal and numerical ability, following directions and general knowledge. It set the pattern of mass group testing the ACB inherited.
The non-verbal counterpart to the Army Alpha, given to illiterate, unschooled or non-English-speaking recruits. It was an early admission that a single verbal test could not classify everyone.
Thurstone argued for seven primary abilities rather than one general factor. That is the theoretical case for scoring a recruit on several aptitudes, as the ACB's composites did.
The classroom version of Thurstone's seven-factor battery. It showed that a multi-score profile could be given to whole groups at once, years before the Army adopted the approach.
A clinical battery from the same years that went the other way: Wechsler combined seven memory subtests into one Memory Quotient, where the ACB split ability into separate job-linked areas.