We asked the user to evaluate the demand of the tasks using the NASA TLX Likert 7-point scale across six categories.
- Mental Demand: How mentally demanding was the task?
- Physical Demand: How physically demanding was the task?
- Temporal Demand: How hurried or rushed was the pace of the task?
- Performance: How successful were you in accomplishing what you were asked to do?
- Effort: How hard did you have to work to accomplish your level of performance?
- Frustration: How insecure, discouraged, irritated, stressed, and annoyed wereyou?
The lower an index is, the more demanding (worse performing) the user finds the task.