This report summarizes the research results and provides a reference. The basic question addressed was, "Is performance on multi-component tasks predicted by performance on the individual components performed separately?" In the first series of experiments, a dual task involving memory and verbal processing components to predict a psycholmetric measure of verbal ability was used. The two types of measures predicted performance on the criterion verbal ability measure equally well. In the second experimental series, ability to detect visual and auditory targets in single channel, focused attention, and divided attention conditions were compared. Performance in the single channel conditions predicted performance in focused and divided attention conditions. Performance on a simple secondary task executed during an easy primary version of the primary task. Dual task performance provided information unavailable from the single task counterpart. The theoretical basis of this research was provided by a "general resource" theory of attention, in which all mental processes are seen as drawing on the same pool of attentional capacity. The Production Activation Model, a more explicit model of inter-task interference, was developed. (Author/DWH)