Here are some helpful tips on how to measure and present usability, and (more importantly) improve your UX process!
Whether you’re in the early stages of investigating problems to be solved, or you’re user-testing higher fidelity prototypes, “usability” is an important aspect to consider at every stage of the design process.
According to Nielsen Norman group, usability is an attribute that assesses how easy user interfaces are to use. The word “usability” also refers to methods for improving ease-of-use during the design process.
“Accessibility” is a term which falls under the umbrella of usability; it refers to an attribute through which “people with disabilities can perceive, understand, navigate, and interact with and contribute to the web”.
5 Qualities of Usability
Usability is defined by five quality components:
- Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
- Efficiency: Once users have learned the design, how quickly can they perform tasks?
- Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency?
- Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?
- Satisfaction: How pleasant is it to use the design?
How to Measure Usability
ISO/IEC 9126-4 Metrics recommends that usability metrics should include:
- Effectiveness (ex. Completion) The accuracy and completeness with which users achieve specified goals.
- Efficiency (ex. Time on Task) The resources expended in relation to the accuracy and completeness with which users achieve goals.
- Satisfaction (ex. Questionnaire) The comfort and acceptability of use.
The System Usability System (SUS) questionnaire is an industry standard, simple set of questions presented to participants at the end of a task set, useful for measuring usability.
Participants are asked to score the following ten items with one of five responses (from “Strongly Agree” to “Strongly disagree”):
- I would like to use this system frequently.
- I found the system unnecessarily complex.
- I thought the system was easy to use.
- I would need the support of a technical person to be able to use this system.
- I found the various functions in this system were well integrated.
- I thought there was too much inconsistency in this system.
- I would imagine that most people would learn to use this system very quickly.
- I found the system very cumbersome to use.
- I felt very confident using the system.
- I needed to learn a lot of things before I could get going with this system.
Note: check out the following resources to learn more about usability testing and the System Usability System:
- Usability3 Metrics to Measure and Quantify UsabilityJoel
- UXA Quick Definition of “Usability Testing”Joanna Ngai
How to Present Usability Results
These three tips will help you present and communicate your usability results to team members, stake holders, and clients.
1. Give Context
Give a background summary to quickly brief your audience on the subject matter. Show relevant visuals to accompany qualitative or quantitative results gives the conclusion more impact and reminds your audience the key insights of your findings and makes them more believable and influential.
2. Make Changes Actionable
Often the change which is clear to the researcher may go through several communication channels. Avoid any chance for confusion and spell out recommended changes. People often don’t read through long reports, so a summary of actionable changes by topic makes scanning easier.
Reporting the severity of the problems found is a great way to help your product team prioritize changes. As every change requires a trade-off of time and resources, it is helpful to give your audience a high level view of what must be changed vs. what are minor issues.
Understanding how to measure and present user research findings well is key to driving change in your product. Following these best practice guidelines is a good way to ease communication between users and project teams.