Aptitude Testing Inspired by Information Processing: A Test of the Four-Sources Model

The four-sources model of human abilities posits that individual differences in performance on cognitive tasks are due to differences in working-memory capacity, information-processing speed, the breadth of declarative knowledge, and the breadth of procedural knowledge. To test this model, 310 civilian volunteers were administered a 25-test battery, consisting of verbal, quantitative, and spatial tasks designed to reflect each of the four sources. Confirmatory factor analysis was performed on the variance-covariance matrix of test scores to test the four-sources model and plausible alternatives. The best-fitting model was one that included both the four-sources factors and three content factors. Hierarchical and nonhierarchical models fit about equally well. From additional data on the Armed Services Vocational Aptitude Battery, latent-factor correlations suggested that working-memory capacity overlapped considerably with psychometric general ability (r = .99) and breadth of declarative knowledge overlapped with psychometric verbal ability (r = .97), but information-processing speed was distinct from psychometric perceptual speed (r = .16).