The Department of Defense directed that the military services move toward the use of a common aptitude battery for satisfaction of their personnel selection requirements. The content of existing service classifications were studied during the initial phase of battery redesign. Elements from the Army Classification Inventory, the Navy Vocational Interest Inventory, and the Air Force Vocational Interest Choice Examination were combined to form an interest inventory. An item pool of 2,700 test items was administered to 500 to 600 subjects at basic training centers and at the Armed Forces Entrance and Examination Stations. Three forms of the battery (5, 6, and 7) were then developed and administered to approximately 4,500 Army, Navy, Air Force, or Marine Corps applicants. Service norms were developed from a sample of 16,000 of these subjects. The reliability of the three test forms was found to be high, particulary for the composite scores. (DSE)