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WAI: Strategies, guidelines, and resources to make the Web accessible to people with disabilities

This is an outdated draft and should not be referenced or quoted.
The latest version is at: www.w3.org/WAI/intro/usable

[Early Rough Concept Draft]
Web Accessibility and Usability

See also: Accessibility - W3C

Page Contents

Editor note: Examples of alternative titles include:


[@@@ main point: provide a brief introduction to the document.]

This page explores the relationship between web accessibility and usability in the context of standards, guidelines, and conformance. It highlights the overlapping benefits and addresses some questions about making websites, browsers, assistive technologies, and other web tools accessible and usable by people with disabilities.

Understanding Accessibility

[@@@ main points: define the scope of accessibility; explain that it has aspects specific to people with disabilities and aspects that are technical (more so than typcially in usability); explain the benefits of accessibility for everyone (and point to the business case for more background).]

Accessibility is about ensuring an equivalent user experience for people with disabilities. For the web, it means that people with disabilities can perceive, understand, navigate, and interact with websites and tools, and that they can contribute equally without barriers. Accessibility is not an option, it is a human right, as recognized in the UN Convention on the Rights of Persons with Disabilities (CRPD).

Some accessibility requirements are more specific to people with disabilities. For example, they ensure that websites work well with assistive technologies such as screen readers that read aloud web pages, screen magnifiers that enlarge web pages, and voice recognition software that is used to input text. Some of these requirements are technical and relate to the coding rather than to the visual appearance of websites.

Most accessibility requirements benefit people with and without disabilities. While they are general usability principles, they are included in accessibility standards because they can be significant barriers to people with disabilities. For example, being able to use a website without a mouse is good usability, and it an accessibility requirement because people with some physical and visual disabilities cannot use a mouse at all. Thus products designed to meet accessibility requirements are more usable for everyone.

Understanding Usability

[@@@ main points: define the scope of usability; explain UCD as a process to help implement usability; explain the benefit of involving people with disabilities in design processes, such as in usability testing in UCD.]

Usability means designing products and services to be effective, efficient, and satisfying. Usability includes design principles with considerations for users and their context. For instance, the abilities, skills, and preferences of web users, and the devices they are using to access the Web. Usability also includes methods for implementing and measuring usability, much of which can be used to meet web accessibility principles.

In particular user-centered design (UCD) focuses on usability goals, user characteristics, environment, tasks, and workflow in the design of an interface, such as that of a website, web application, browser, and other web tools. UCD is an iterative process with well-defined methods and techniques for analysis, design, and evaluation from the first stage of projects, through implementation.

People with disabilities are often more sensitive to usability problems. For example, a large number of links poorly organized on a web page will be more of a problem for people with some types of cognitive, physical, or visual disabilities. Involving people with disabilities in UCD processes such as usability testing is therefore particularly beneficial because it helps identify issues more easily.

Usable Web Accessibility

[@@@ main points: explain that usability and accessibility are ideally combined into a single process.]

Usable web accessibility combines usability and accessibility to ensure that websites and web tools are usable by people with disabilities. [[user experience]]

Real People

[@@@ main points: emphasize the human factor of accessibility and that it is about real people (as opposed to ticking-off checkboxes); and that developers need to learn the basics first in order to manage accessibility effectively.]

Usable web accessibility means meeting the needs of real people using the Web. An effective way to meet the needs of real people is to involve users early and throughout the design process. This helps developers understand essential basics of how people with disabilities use the Web. For example, observing people with disabilities complete complex tasks on an accessible website and then struggle with the same tasks on an inaccessible website helps developers better understand accessibility barriers and solutions.

While including users with disabilities is key to making accessibility efforts more effective and more efficient, that alone cannot address all issues. Even large projects cannot cover the diversity of disabilities, adaptive strategies, and assistive technologies. That is the role of accessibility standards.

Technical Standards

[@@@ main points: explain the role of techical standards for developing accessible and usable products; in particular to highlight the role of techniques to provide practical guidance for specific situations.]

The W3C Web Accessibility Initiative (WAI) develops a set of guidelines that are internationally recognized as the standard for web accessibility:

The WAI guidelines include considerations for people with auditory, cognitive, neurological, physical, speech, and visual disabilities, including people with age-related impairments.

The WAI guidelines are accompanied by supplementary techniques that help explain how to implement the requirements in practice. For instance, WCAG 2.0 defines a success criterion for text alternatives and provides techniques to help meet this requirement. It also provides advisory techniques that help improve and optimize the accessibility of websites for people with disabilities.

WCAG 2.0 success criteria and techniques are provided in a customizable quick reference.

Optimizing Accessibility

[@@@ main points: re-iterate that usability processes can (and should) be used to implement accessibility, and to optimize it as needed; emphasize that optimizations, including adaptibility approaches, are part of accessibility.]

Usability methods and techniques, such as UCD processes, can be used to better understand the users of a particular website or tool. For instance, to optimize the design for particular audiences or situations, such as to improve the usability of an online learning system for students with hearing disabilities or such. This could mean emphasizing particular requirements that are more relevant to those users or situations, such as using simple language and sign language videos to better accommodate people with hearing disabilities.

Fortunately the Web is highly adaptable and allows the same content to be presented to users in different ways according to their needs and preferences. For example, websites can provide content in different colors, layouts, or presentation formats to meet the needs of a particular user. In some cases websites could even provide different content that serves the same purpose. For example, different versions of a course, to help students with different learning styles to complete the same curriculum.

Websites and tools that are optimized to better meet the usability needs of particular audiences can meet web accessibility standards and be usable to a wider audience. For instance, by making default presentations accessible, even if individual alternative presentations of the content are optimized to particular audiences and are not accessible to all users.

Usability Beyond Accessibility

[@@@ main points: promote coordination between usability and accessibility, in particular by inviting contribution to WAI work by researchers; highlight the negative impact of not coordinating and building on existing work.]

Usability issues that affect people with disabilities disproportionally need to be addressed by corresponding accessibility requirements. For instance, clear navigation mechanisms help everyone yet unclear navigation mechanisms can be particularly confusing for people with visual and cognitive disabilities. [@@ continue to say: ...WAI welcomes comments and feedback on existing standards, even if they may only be considered in future iterations.]

In some cases the combination of usability issues can create accessibility barriers. For instance, relying on settings that are difficult to find or to configure in common browsers, such as settings to change the colors for text, is an obstacle for some users. In this case, the browser could be improved to help users customize the settings and the website could be improved to help educate users on how to customize their browsers. Such issues can be identified by involving users, for instance by using UCD methods and techniques. [@@ continue to say: ...WAI welcomes the contribution of additional techniques, in particular those that help address accessibility issues in particular design situations (such as in the example above).]

In other cases usability issues are not specifically related to people with disabilities and are not addressed by accessibility requirements. For instance, some usability issues that relate to computer skills are barriers for older web users but they are not regarded as accessibility barriers specifically for people with disabilities. In fact, they are often barriers for people with lower income, people in less developed regions, and many more. [@@ continue to say: ...developing such general usability requirements is important but when doing so, make sure to harmonize (see next paragraph).]

Because usability and accessibility are so closely related, it is essential to ensure interoperability with existing accessibility standards when developing usability recommendations. For instance, an extensive literature review on web accessibility for older users identified a significant lack of references to the WAI guidelines in design recommendations, even though the WAI guidelines address the outlined accessibility needs. In some cases design recommendations that were developed disjointly conflict with the existing WAI guidelines, even though they aim to address the same issue.

WAI invites participation and welcomes contribution of comments, research findings, and techniques: