A multivariate modeling approach was developed to assess the impact of changes in aptitude requirement minimums on U.S. Air Force technical training outcomes. Initially, interviews were conducted with technical training personnel to identify significant student inputs, course content, and training outcome variables. Measures of these variables were formulated on the basis of personnel records and routinely available training documents, znd data were assembled for over 5,000 trainees in 39 initial-skills courses at five Air Force bases. A cross-validation sample consisted of about 1,000 trainees in nine courses. Using formal path analysis (LISREL V computer program), an empirical model of the training process was developed. Although aptitude was one of the best predictors of the quality of student performance, it interacted with a vaiiety of other student input and course content variables in determining training outcomes. Course content variables tended to be defined by course subject-matter difficulty, occupational difficulty, and manpower requirements, Counseling mediated the relationship between training performance and distal training outcomes such as retraining time and student elimination. Appendices present sample interview questions, an Air Force policy document on student measurement (with reporting forms), and tables of input statistics and path analysis results.