Measurement of Taskload and Performance in a Dynamic Multi-Task Experiment

This paper discusses an experimental paradigm for measuring human performance under time pressure. Participants were presented with four simultaneous number-entry tasks. Entry could occur only within a discrete window of opportunity, represented visually by a target range within a variable-speed progress bar. Participants could view only one task at a time, thus performance required scanning and sampling of all four tasks. Sampling behavior (mouse movements to the vicinity of one of the four tasks) was manipulated via access effort; blocks of trials presented either a half or full second lag before a target task would become visible. Participants' performance was evaluated by the proportion of responses completed within the required window of opportunity as well as the proportion of a window of opportunity that elapsed before the onset of a response. Results indicate a decrease in such performance as a result of display lag manipulation. The potential for the use of this paradigm in developing predictive measures of performance is discussed.