The Mathematics Department of the Test Development Division developed an item classification system and provided a pool of 426 classified items from which a 50-item test was to be selected. The pool was purposely constructed to insure the possibility of assembling a test to meet specifications by using a variety of previously assembled tests, including some that had been built to the same specifications as the one to be selected. For each item, the information provided consisted of an identification number, which was the accession number already assigned for Test Development file records, and classification over the following six dimensions: (1) major content area, (2) specific content within major area, (3) grade level, (4) type of ability tested, (5) discrimination index, and (6) difficulty level. Although all the categories were numerically coded, only the biserial correlations and the difficulty levels could be considered to be on an interval scale, the remainder simply described ordinal or nominal categories. The 426 items were coded and keypunched, one item to a card record, and then put on magnetic tape. A file of items in order of accession number was then set up for rapid clerical assembly of the test from computer output.