Usability testing is a key method and one of the most important tools in UX. Usability testing evaluates a product, service, or tool with people that are representative of real users. Usability test facilitators directly observe people using a system to complete tasks.

Usability testing is observed behavioral research that mainly includes qualitative research but may also use quantitative methods for supporting data. The core of usability testing is qualitative, directly observing people attempting tasks in a system. This should answer questions of what problems do you observe people having and what is the cause of the problems? Quantitative methods may include analytics that answer questions of how many people experience a problem or how long it takes them to complete a task. Quantitative methods should be done as a complement to qualitative methods.

Usability testing can be done anytime during the product development lifecycle. Testing can be done on competitors' products, on existing user interfaces, with early prototypes, or with designs. The earlier usability testing is done, the larger the benefit. Problems discovered with a prototype are easier and less expensive to change before they are built into the product.

Benefits of Usability Testing

• Learn if people can complete target tasks.
• Benchmark and improve the length of time it takes to complete tasks.
• Receive direct feedback and see actual user behavior for target users.
• Quickly discover problems and their severity with the interface with relatively few tests.
• Observe user behavior and success without relying on self-reporting.
• Discover unresolved problems in competing products.

A usability study should first start with a test plan. Test plans enable multiple facilitators to do tests while producing comparable results, and maximizes the value from testing.

Typical Test Plan Includes

• Define research goals
• Materials needed
• Date/location of test
• UI version or feature being tested
• Target users
• Tasks to complete
• Define success paths
• Measurements of success/failure