How Accurately Can an Observer Assess Participant Self- Reported Workload?

摘要

Subjective workload assessments are used often in human factors, almost always from the perspective of the one performing the task. How well would an observer or experimenter be able to subjectively rate the mental workload of a task being performed by a subject? In this experiment, participants formed groups of two in which one acted as an experimenter and the other as a subject. The experimenter administered three types of distractor tasks to the subject while the subject held a consonant triad in their working memory. The three tasks were a high difficulty task (counting), a medium difficulty task (writing), and a low difficulty task (drawing). Both experimenter and subject then filled out a NASA-TLX for all three task types. Roles were switched and the process repeated. Significant differences in rating were found for the high difficulty but not the low difficulty task, with the medium difficulty task in between.