A program of theoretical and empirical research focusing on the ability determinants of individual differences in skill acquisition is reviewed. An integrative framework for information-processing and cognitive ability determinants of skills is reviewed, along with principles for ability-skill relations. Experimental manipulations were used to evaluate the cognitive ability demands associated with information processing parameters of skilled performance. Experiments described include basic information processing (a noun-pair look-up task) and complex problem solving decision making (a terminal radar approach control simulation task--TRACON). Generalization and applications to the public sector (development of an ability-based selection battery for Federal Aviation Administration air traffic controllers) are described briefly. Finally, new theoretical and empirical developments regarding the construct of intelligence as typical performance, and general personality-ability relations are described. Ten figures and one table summarize study results. A list of 80 references is included. Appendix A contains a table of noun-pair results (one figure), and Appendix B described the TRACON task (one figure). (Author/SLD)