A study dealt with the use of the Position Analysis Questionnaire (PAQ) within a job component validity framework as the basis for estimating aptitude requirements of jobs represented by scores on commercially available tests as contrasted with scores on General Aptitude Test Battery (GATB) tests. Procedures generally consisted of the use of job dimension scores based on previous principal components analyses of the PAQ as the predictors of four types of test-related criteria, as follows: the mean test scores of incumbents on the individual jobs; the score one standard deviation below the mean of the incumbents on the individual jobs; validity coefficients; and an indication as to whether the test would be valid. Analyses were carried out for five constructs (general intelligence, verbal aptitude, numerical aptitude, spatial aptitude, and clerical perception) using all four criteria for those jobs for which adequate test data and PAQ analyses were available. In summary: (1) Previous research with the use of the PAQ as the basis for establishing aptitude requirements has dealt exclusively with test data from the GATB tests, but (2) the results of this study indicate clearly that such data can also be used in establishing aptitude requirements in terms of commercial tests that presumably measure the same constructs. (TA)