A difficult-to-get technical report by Dr. Diane Damos and Thomas Smist has been released on ResearchGate.  This report describes three of the earliest studies of individual differences in multiple-task (timesharing) response strategies. At the time this research was begun, nothing was known about the response strategies observed in Damos and Wickens (1980).

Experiment I examined whether the response strategies used to perform two discrete information processing tasks reflected individual differences in information processing at high levels of workload or simply were selected at random. Each subject’s response strategy first was identified as either a simultaneous, an alternating, or a massed strategy. Then some of the subjects were asked to change strategy. The results indicated that the massed response strategy subjects had less well-developed timesharing skills and were not able to process information under multiple-task conditions as well as the other subjects regardless of the response strategy used. The results were interpreted as evidence that response strategies represent fundamental differences in multiple-task information processing.  This study subsequently was published in 1983 in Human Factors (25, pp. 215- 226) with A.C. Bittner, Jr. as Individual differences in multiple‑task performance as a function of response strategy.

Experiments II and III attempted to locate the source of the differences observed in Experiment I. Experiment II examined the relation between multiple-task performance in two different task combinations and cerebral lateralization, multiple-limb coordination, and four tests of cognitive style. No significant relations were found.

In Experiment III each subject’s response strategy first was identified. The subjects then were asked to perform a discrete task combination consisting of a classification task and a choice reaction time task. Estimates of the duration of various information processing stages were obtained from the choice reaction time data. Analyses revealed that the duration of information processing stages did not differ significantly between strategy groups. Some of the data, however, suggested that individuals using the alternating response strategy may process information faster under multiple-task conditions than others.

This technical report ends with a general interpretation of the results from the three studies and gives recommendations for future research.

https://www.researchgate.net/publication/345819022_Response_Strategies_and_Individual_Differences_in_Multiple-Task_Performance