The Position Analysis Questionnaire (PAQ), a structured job analysis questionnaire that provides for the analysis of individual jobs in terms of each of 187 job elements, was used to establish the job component validity of certain commercially-available vocational aptitude tests. Prior to the general analyses reported here, a statistical analysis was carried out with the attribute profile data of the General Aptitude Test Battery (GATB) of the U.S. Employment Service as the possible basis for the prediction of aptitude requirement of jobs. In addition, a cluster analysis was carried out using a hierarchical grouping technique as applied to scores on 13 "overall" dimensions of the PAQ. The final analyses consisted of using as a sample jobs for which test data and PAQ analyses were available. A separate analysis was carried out for each of five of the constructs represented by the GATB tests. These included general intelligence, verbal aptitude, numerical aptitude, spatial aptitude, and clerical perception. Results of the analyses generally supported the potential use of a structured job analysis procedure such as represented by the PAQ as the basis for the establishment of aptitude requriements for jobs for at least certain aptitudes. (Author/MV)