Presented are the methodology and results of an equipercentile equating study in which subtests of the following three editions of multiple aptitude test batteries, in widespread use in 1960, were equated to the tests of the Project TALENT test battery: Flanagan Aptitude Classification Tests (1957); Differential Aptitude Tests (1947) and; the General Aptitude Test Battery (1952). Since Project TALENT tests were administered to large samples of students representative of the entire American secondary school population, the purpose of the study was to enable the three non-TALENT test batteries to be interpreted in terms of Project TALENT test norms. The study reports equivalent scores for groups of 257 boys and 286 girls who took each of the tests in question. The equating procedure is fully described in terms of: estimating reliabilities, using comparable true scores rather than raw scores; correction for growth on the three sets of non-TALENT test scores, since these were taken by students approximately six months after having been administered TALENT tests; and the seven point and five point smoothing formulas employed. Tables of the tests equated, statistical data, and one decimal raw-score equivalents on selected TALENT tests for integral raw-scores on the equatable non-TALENT subtests are provided. (AEF)