What is Usability?
From UPA in the ISO 9241 standard:
Usability is an approach to product development that incorporates direct user feedback throughout the development cycle in order to reduce costs and create products and tools that meet user needs. There are many definitions of usability from books by usability professionals.
Two international standards define usability and human-centered (or user-centered) design:
- “[Usability refers to] the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.” – ISO 9241-11
- “Human-centered design is characterised by: the active involvement of users and a clear understanding of user and task requirements; an appropriate allocation of function between users and technology; the iteration of design solutions; multi-disciplinary design.” – ISO 13407
The business benefits of adding usability to a product development process include:
- Increased productivity
- Increased sales and revenues
- Decreased training and support costs
- Reduced development time and costs
- Reduced maintenance costs
- Increased customer satisfaction
More definitions on books about Usability
Usability means that the people who use the product can do so quickly and easily to accomplish their own tasks. This definition rests on four points: (1) Usability means focusing on users; (2) people use products to be productive; (3) users are busy people trying to accomplish tasks; and (4) users decide when a product is easy to use.
- Janice (Ginny) Redish and Joseph Dumas, A Practical Guide to Usability Testing, 1999, p. 4
After all, usability really just means that making sure that something works well: that a person of average (or even below average) ability and experience can use the thing – whether it’s a Web site, a fighter jet, or a revolving door – for its intended purpose without getting hopelessly frustrated.
- Steve Krug, Don’t Make Me Think, 2000, p. 5
Usability starts with a philosophy – a belief in designing to meet user needs and to focus on creating an excellent user experience – but it is the specific process and methodology that produce the real goal of usability. A new usability process starts by looking at who uses a product, understanding their goals and needs, and selecting the right techniques to answer the question, “How well does this product meet the usability requirements of our users?”
- Whitney Quesenbery
It is important to realize that usability is not a single, one-dimensional property of a user interface. Usability has multiple components and is traditionally associated with these five usability attributes: learnability, efficiency, memorability, errors, satisfaction.
- Jakob Nielsen, Usability Engineering, 1993, p. 26
Usability is a measurable characteristic, that is present to a greater or lesser degree, that describes how effectively a user can interact with a product. It can also be thought of as how easy a product is is to learn and how easy it is to use.
- Jeff Axup, UserDesign
Source: upassoc.org
