Definition - What does Usability mean?
Usability is the degree of ease with which products such as software and Web applications can be used to achieve required goals effectively and efficiently. Usability assesses the level of difficulty involved in using a user interface. Although usability can only be quantified through indirect measures and is therefore a nonfunctional requirement, it is closely related to a product's functionality.
Techopedia explains Usability
Usability assessment generally includes studies of the clarity of websites and computer programs. These studies are conducted by usability analysts. When a product is deemed to be have good usability, this means it is easy to learn, and efficient and satisfying to use.
Usability design considers who the users are, what they know and how they learn, users' general backgrounds, and the context in which they use a given product. It also considers whether users accomplish the tasks at the desired speed, the training required to use the program, supporting materials available to help users, the chance of recovery from errors and the program's ability to meet the needs of disabled users.
Usability is based on three design principles:
- Iterative focus on the user and the task
- Iterative design
- Empirical measurement
There are several methods that can be used to evaluate usability:
- Cognitive Modeling: Creates computational models to estimate how long people take to perform specific tasks
- Inspection: Involves program evaluation by an expert reviewer. Tasks in this method are timed and recorded, making it relatively qualitative in nature
- Inquiry: Includes collecting qualitative data from users as well as task analysis that specifies the tasks users have to accomplish in order to achieve their desired goals
- Prototyping: The usability of a system is refined and validated
- Testing: The testing of subjects for quantitative data