Usability

Usability is much more than a measure of how easily a thing (typically a software application or a piece of hardware) can be used. It's not so much about the intentions of designers as it is about the needs of users. Usability addresses the full spectrum of impacts upon user success and sastisfaction. Usability is accomplished through user-centered (not necessarily user-driven) design. The usability engineer provides a point-of-view that is not dependent upon designers' goals because the usabiity engineer's role is to act as the users' advocate. For example, after interacting with users, the usability engineer may identify needed functionality or design flaws that the designers had not anticipated.

Software Development magazine says:

The International Standards Organization (ISO) defines usability as “the effectiveness, efficiency and satisfaction with which specified users achieve specified goals in particular environments.” [1]

Usability includes considerations such as:

• What do users want or need to do ?
• What is the general background of the users ?
• What is the context in which the user is working ?
• What has to be left to the machine ? What to the user ?

Answers to these can be obtained by conducting user and task analysis at the start of the project.

Other considerations include:

• Can users easily accomplish their intended tasks? For example, can users accomplished intended tasks at their intended speed?
• How much training do users need?
• What documentation or other supporting materials are available to help the user? Can users find the solutions they seek in these materials?
• What and how many errors do users make when interacting with the product?
• Can the user recover from errors? What do users have to do to recover from errors? Does the product help users recover from errors, for example, does software present informative, non-threatening error messages?
• Are there provisions for meeting the special needs of users with disabilities?(Note: Is this item confusing usability with accessibility?)[Response, not at all. Accessibility is an integral part of usability.]

Examples of ways to find answers to these and other questions are user-focused requirements analysis, building user profiles, usability testing.

Usability is now recognized as an important software quality attribute, earning its place among more traditional attributes such as performance and robustness. Indeed various academic programs treating usability as a core concern have begun to appear; see, e.g., the Human-Computer Interaction Program at Carnegie Mellon University.

Usability is the software specialization of the larger topic of human factors and ergonomics, although the term is also applied to document design.

See also

• Internationalization

External links

• Design Basics An introduction to some of the basics of usability design, mostly by example.
• CMU HCII website
• Web Design Reference - A huge mega-reference (over 3,000 links) of information and articles dedicated web design and development. The site advocates accessibility, web standards, usability, evaluation and testing and many related topics. It features a listserv and RSS feed for site updates.
• Usability Views A collection of thousands of links to usability related articles.

• The Indo European Systems Usability Partnership website
• CHIPlace Forum on Computer Human Interaction website
• Human Computer Interaction Bibliography website
• The Center for Knowledge Societies An ethnographic and usability research organization that focuses on innovating for non traditional and underserved user communities in South Asia and other emerging economies.