NASA Task Load Index (TLX)
This is the most up to date version of this scale.
Construct Summary
The authors define workload as consisting of six main dimensions: mental demands, physical demands, temporal demands, effort, frustration, and performance. These dimensions are thought to:
“relate to the demands imposed on the subject (mental, physical, and temporal) and … to the interaction of a subject with a task (effort, frustration, and performance)” (p. 2).
Rating = 38%
| Check? | Guideline Item |
|---|---|
| ✓ | Is the construct defined? |
| ✓ | Does the final version of the items capture the construct as it has been defined by the authors? |
| ✓ | Is the item generation process discussed (e.g., literature review, Delphi method, crowd-sourcing)? |
| ✖ | Person to items 10:1 for the initial set of items? |
| ✖ | Did they perform an EFA, PCA, Rasch, or similar test to determine the item to factor relationship? |
| ✖ | Did they describe how they determined number of factors? |
| ✖ | Did they report the full initial set of items? |
| ✖ | Did they provide loadings (EFA) or item fits (Rasch) of all items? |
| ✖ | Is there a description of the item removal process (e.g., using infit/outfit, factor loading minimum value, or cross-loading values)? |
| ✓ | Did they list the final items included in the scale? |
| ✖ | Did they include a factor structure test (e.g., second EFA, CFA, DIF, test for unidimensionality when using Rasch, or similar)? |
| ✖ | Was a measure of reliability (e.g., Cronbach’s alpha, McDonalds Omega_h or Omega_t, Tarkkonen’s Rho) reported? |
| ✓ | Was a test of validity (e.g., predictive, concurrent, convergent, discriminant) reported? |
Comments None.
Reviewed by Experts ✓
Downloads
PAPER
Hart, S. G. (1986). NASA task load index (TLX).
PDF of scale as well as instructions for administration and scoring are located in the paper.
Final Scale Items (6 total):
Participants are first asked to provide their ratings/responses to the questions below. Then they are asked to weight the importance of each dimension using a ranking task. The ratings and weights are combined to produce a final score. See paper for more details.
Mental Demand
How much mental and perceptual activity was required (e.g., thinking, deciding, calculating, remembering, looking, searching, etc.)? Was the task easy or demanding, simple or complex, exacting or forgiving?
Participants given response scale with 20 equally spaced intervals anchored by the endpoints “low/high”
Physical Demand
How much physical activity was required (e.g., pushing, pulling, turning, controlling, activating, etc.)? Was the task easy or demanding, slow or brisk, slack or strenuous, restful or laborious?
Participants given response scale with 20 equally spaced intervals anchored by the endpoints “low/high”
Temporal Demand
How much time pressure did you feel due to the pace at which the tasks or task elements occurred? Was the pace slow and leisurely or rapid and frantic?
Participants given response scale with 20 equally spaced intervals anchored by the endpoints “low/high”
Effort
How hard did you have to work (mentally and phyiscally) to accomplish your level of performance?
Participants given response scale with 20 equally spaced intervals anchored by the endpoints “low/high”
Performance
How successful do you think you were in accomplishing the goals of the task set by the experimenter (or yourself)? How satisfied were you with your performance in accomplishing these goals?
Participants given response scale with 20 equally spaced intervals anchored by the endpoints “good/poor”
Frustration Level
How insecure, discouraged, irritated, stressed and annoyed versus secure, gratified, content, relaxed and complacent did you feel during the task?
Participants given response scale with 20 equally spaced intervals anchored by the endpoints “low/high”