Web Style Guide third edition

by Patrick J. Lynch
and Sarah Horton

2 Universal Usability
A Basis for Universal Usability

The concept of universal usability is informed by several initiatives, primarily accessibility, usability, and universal design.


Since the World Wide Web Consortium established the Web Accessibility Initiative in 1999, the imperative of web accessibility has gained the attention of individuals, organizations, and governments worldwide. wai promotes best practices and tools that make the web accessible to people with disabilities. They also safeguard universal web access by providing expert input for development initiatives to ensure that accessible designs can be accomplished using current and future web technologies.

Web accessibility is a critical element of universal usability. The guidelines produced by wai and other accessibility initiatives provide us with techniques and specifications for how to create universally usable designs. They ensure that designers have the tools and technologies needed to create designs that work in different contexts.

Usability and user-centered design

Usability is both a qualitative measure of the experience of using a tool and a phenomenon that can be measured and quantified as a concrete means to judge a design’s effectiveness. Quantitative usability metrics include how quickly we complete tasks and how many errors we make in the process. But usability can also be measured by qualitative measures, such as how much satisfaction we derive in using a tool. “Learnability” is another important measure: how quickly we learn to use a tool and how well we remember how to use it the next time. Usability has an impact not only on our effectiveness but also on more fundamental qualities, such as loyalty. The more usable the tool, the better we feel about using it and, in the case of web sites, the more likely it is that we will return to the site.

The most common method for achieving usability is user-centered design (ucd). ucd includes user-oriented methods such as task analysis, focus groups, and user testing to understand user needs and refine designs based on user feedback. ucd involves determining what functionality users want in a product and how they will use it. Through iterative cycles of design, testing, and refinement, ucd practitioners continuously check in to make sure they are on track-that users like and will be successful using the design.

Universal usability arises from user-centered design, but with a broad and inclusive view of the user. ucd is applied to the task of designing web sites that are easy to learn and use by a diversity of users, platforms, and usage contexts.

Universal design

Universal design incorporates access requirements into a design, rather than providing alternate designs to meet specific needs, such as large print or Braille editions for vision-impaired readers. A common example of universal design in the built environment is ramped entryways, which can be used by everyone and eliminate the need for a separate, handicapped entrance. Universal design has many benefits. A single design that meets broad needs is often less costly than multiple designs. And designs that anticipate a diverse user population often have unanticipated benefits. For example, curb cuts in sidewalks are intended to help mobility- and vision-impaired users, but many others benefit, including people making deliveries, pushing a stroller, or riding a bike.