nasa-tlx
The NASA-TLX is a widely used subjective workload assessment tool. It consists of six subscales: Mental Demand, Physical Demand, Temporal Demand, Performance, Effort, and Frustration. The NASA-TLX is designed to assess the perceived workload of a task and is commonly used in human factors and ergonomics research. We provide a component of the NASA-TLX itself, and a sequence that includes a source of load evaluation. The source of load evaluation is based on the pairwise weighting procedure described in the NASA-TLX manual.
Referenceโ
Hart, Sandra G., and Lowell E. Staveland. "Development of NASA-TLX (Task Load Index): Results of empirical and theoretical research." Advances in psychology. Vol. 52. North-Holland, 1988. 139-183.
DOI: 10.1016/S0166-4115(08)62386-9
Available Componentsโ
- nasa-tlx
- source-of-load
Available Sequencesโ
- nasa-tlx-with-source-of-load-evaluation
Additional Descriptionโ
Source of Workload Evaluation (Pairwise Weighting Procedure)โ
Reference: NASA TLX manual (Section 2.2)
This step of the NASA-TLX assesses the relative importance of different factors that contribute to a person's experience of workload during a task. Rather than assuming all workload components are equally important, this procedure captures individual differences in how workload is perceived.
Participants are presented with 15 pairwise comparisons between the six NASA-TLX subscales:
- Mental Demand
- Physical Demand
- Temporal Demand
- Performance
- Effort
- Frustration
For each pair, participants are asked to select the factor that contributed more to their workload experience in the given task.
How It Worksโ
Each chosen subscale earns one point (a "tally mark").
After 15 comparisons, each subscale has a weight from 0 to 5.
These weights reflect the participant's personal weighting of each workload dimension.
How to Use the Resultโ
After task performance, participants also rate the magnitude (0โ100) of each of the six subscales.
For each subscale: Adjusted Score = Raw Rating ร Weight
The overall workload score is calculated by summing all adjusted scores and dividing by 15: Overall Workload = ฮฃ(Adjusted Scores) รท 15
This weighted workload score accounts for both perceived intensity and individual prioritization, improving sensitivity and personalization in workload analysis.