Reference entry content
Concept facts
Task success is a UX evaluation measure that describes whether a user completes a specified task or goal under defined evaluation conditions.
- Also known as
- Task completion, completion rate, success rate.
- Used in
- Usability testing, product evaluation, service journey evaluation, form and transaction review.
- Interpret with
- Errors, assistance, time on task, confidence, accessibility barriers, satisfaction, and outcome quality.
Plain-language explanation
Task success asks whether a person was able to do the thing the team asked them to do. In a usability test, that might mean submitting a benefit application, finding a service deadline, changing an account setting, or comparing two product options.
The success condition should be defined before the evaluation begins. A technically submitted form may not be a successful task if the person chose the wrong service, misunderstood eligibility, or needed help that would not be available in real use.
Why it matters
Task success connects design quality to observable user outcomes. It provides evidence of whether users can complete defined goals under specified conditions.
Task success should not be used alone as proof of overall UX quality. It is stronger when interpreted with errors, time, confidence, satisfaction, accessibility barriers, and the quality of the final outcome.
Use contexts
- Usability testing.
- Form and transaction evaluation.
- Product or portal review.
- Prototype testing.
- Public-service and development-sector journey review.
Application guidance
Define the task, success condition, allowed assistance, failure conditions, and partial-success rules before testing. Record enough context to explain what happened, not only whether the final step was reached.
Practical example
A social safety net portal asks applicants to check whether they qualify for a benefit program. A participant reaches the final confirmation page, but selects the wrong household category because the eligibility labels use policy language that does not match local household arrangements.
The task should not be counted as fully successful just because the form was submitted. The relevant success condition is whether the applicant reached the correct eligibility outcome with accurate information and without staff correction.
Interpretive boundaries
- Task success does not measure user satisfaction by itself.
- Task success is not always a simple binary outcome.
- Task success depends on a clearly defined task and success condition.
- Task success alone does not establish overall usability or UX quality.
- Task success should be interpreted as evidence about the task and context, not as a judgment of the user.
Applied at Userhub
Task success is relevant when Userhub evaluates whether people can complete important actions in real service, product, and platform journeys.
See Userhub UX Lab for applied UX research and evaluation context.
Sources and references
- ISO. (2018). Ergonomics of human-system interaction – Part 11: Usability: Definitions and concepts (ISO Standard No. 9241-11:2018). International Organization for Standardization.
- National Institute of Standards and Technology. (2001). Common Industry Format for Usability Test Reports (NISTIR 6530). U.S. Department of Commerce.
- Bevan, N. (1995). Measuring usability as quality of use. Software Quality Journal, 4(2), 115-130. https://doi.org/10.1007/BF00402715
- Frøkjær, E., Hertzum, M., & Hornbæk, K. (2000). Measuring usability: Are effectiveness, efficiency, and satisfaction really correlated? Proceedings of the SIGCHI Conference on Human Factors in Computing Systems, 345-352. https://doi.org/10.1145/332040.332455
Cite this entry
APAUserhub. (2026). Task Success. UX Reference. https://userhub.com.bd/reference/task-success/