Time-sharing revisited: Test of a componential model for the assessment of individual differences

Abstract

Time-sharing ability as an individual differences variable in dual task performance was examined using a componential model. Five proposed components were assessed: (1) serial processing ability; (2) an internal model of the system dynamics; (3) performing heterogeneous operations; (4) adaptation to rapidly changing dynamic conditions; (5) parallel processing ability. The approach combined methodologies from experimental psychology and from individual differences research. Forty subjects were given four single task pretests, and then performed a compensatory tracking task in various dual task combinations administered during six sessions over a period of three days. At the conclusion of the experiment the subjects had to perform three different dual task transfer tasks. The results of a factor analysis and a series of stepwise multiple-regression analyses revealed two important dimensions of individual differences in dual task performance: (1) individual differences in cognitive style linked to the concept of field dependence/independence; (2) individual differences in time-sharing ability. The individual differences in cognitive style were identified by the first derived factor. It was defined by the measures that represent serial and parallel processing. Based on the opposing signs, positive for the serial processing measures and negative for the parallel processing measures, it was concluded that this factor is bipolar, representing two distinct strategies. Further-analyses suggested that the strategy differences may be linked to individual differences in field dependence/independence. Individual differences in time-sharing ability were identified by the second derived factor of the factor analysis and through multiple-regression analysis. Based on the results the concept of a ‘process-specific’ time-sharing ability was introduced.