Time Estimation as a Measure of Mental Workload

摘要

Technical systems of different kinds might differ in the mental demands they put on their users while being equally usable in a more conventional sense. Several methods exist that measure mental workload. However, in the everyday practice of usability evaluations, none of these methods seems to be used. This is probably due to the amount of effort needed to use them. The study of our errors in estimation of durations show that errors increase as a function of the amount of attentional resources being needed for other concurrent tasks. This points towards a simple way of estimating mental workload. By asking people to provide estimates of elapsed time after a task, disruptions in their estimates could indicate the mental workload of the task. We conducted a first study aimed at validating this idea with the NASA TLX method. Results show that errors in time estimates correlate significantly with TLX scores.