Measurement

Efficiency

A usability measure concerned with the resources users expend to achieve defined goals in a specified context of use.

Concept facts

Efficiency is the extent to which users achieve specified goals while expending appropriate resources such as time, effort, attention, steps, or support.

Also known as
Task efficiency, interaction efficiency, effort efficiency, resource use
Used in
Usability testing, workflow evaluation, task-time analysis, product comparison, operational systems, service journey evaluation
Interpret with
Effectiveness, task success, time on task, error rate, assistance, cognitive load, accessibility, and task risk

Plain-language explanation

Efficiency asks how much effort or resource is required for users to achieve a task goal. In many usability evaluations, efficiency is measured through time on task, number of steps, number of attempts, assistance needed, or repeated actions.

Efficiency should not be interpreted without effectiveness. A fast task is not useful if the user completes the wrong action, misunderstands the outcome, or submits incorrect information.

Efficiency also depends on context. Some tasks should be quick and routine. Others require careful reading, confirmation, consent, or comparison. The goal is not always speed, but appropriate effort for a correct and confident outcome.

Why it matters

Efficiency affects whether users can complete tasks without unnecessary friction. Excessive effort can lead to abandonment, errors, repeated support requests, staff workload, and reduced confidence in the service.

Efficiency is especially important in high-frequency workflows, administrative systems, customer-support journeys, public-service portals, and professional tools where small delays or repeated steps accumulate over time.

Efficiency also helps teams identify bottlenecks. A task may be effective but still require avoidable effort because users must search, reread, backtrack, wait, or recover from unclear interaction states.

Use contexts

  • Task-time measurement
  • Workflow and process evaluation
  • Transaction and form review
  • Prototype comparison
  • High-frequency operational tools
  • Service journey evaluation
  • Product release assessment

Application guidance

Define the resource being measured before evaluation. Efficiency can include time, steps, clicks, attempts, assistance, recovery effort, or cognitive effort. Do not reduce efficiency to speed unless time is the relevant resource.

Measure efficiency only in relation to a specified task and success condition. A short completion time is not meaningful if the task is incomplete or inaccurate.

For high-impact tasks, efficiency should be interpreted with effectiveness, errors, user confidence, and accessibility. Reducing steps should not remove guidance that users need to act correctly.

Practical example

A corporate compliance dashboard lets managers approve vendor onboarding requests. Managers can approve cases correctly, but they must open separate screens for tax documents, bank verification, procurement category, and risk flag history.

The workflow is effective but inefficient. Reducing unnecessary screen switching can improve decision speed while preserving the required compliance checks.

Interpretive boundaries

  • Efficiency is not the same as speed.
  • Efficiency should not be evaluated without effectiveness.
  • Fewer steps are not always better if important information or safeguards are removed.
  • Efficiency depends on task type, risk, user experience, accessibility needs, and context.
  • Efficiency data should be interpreted with errors, assistance, and outcome quality.

Applied at Userhub

Efficiency is relevant when Userhub evaluates whether people can complete digital tasks without avoidable effort, delay, repeated action, or unnecessary support.

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.
  • Hornbæk, K. (2006). Current practice in measuring usability: Challenges to usability research and applications. International Journal of Human-Computer Studies, 64(2), 79–102. https://doi.org/10.1016/j.ijhcs.2005.06.002
  • 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
  • Card, S. K., Moran, T. P., & Newell, A. (1983). The Psychology of Human-Computer Interaction. Lawrence Erlbaum Associates.

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Cite this entry

APA

Userhub. (2026). Efficiency. UX Reference. https://userhub.com.bd/reference/efficiency/