WebAIM - Web Accessibility In Mind

Constructing a POUR Website
Operable

Input Methods

Not everyone uses a standard keyboard and mouse to access the web. Some people use adaptive devices or alternative devices that accommodate their disabilities or preferences. Content that is only operable through mouse clicks will be inaccessible to users who cannot use a mouse—due to tremors, motor disabilities, or even a lack of hands altogether. A person in this situation is likely to use an adaptive technology of some sort, such as a mouth stick, to manipulate the keyboard. In some cases, the person may be able to use a trackball mouse (e.g., with a mouth stick), but others rely on the functionality of the keyboard. People who are blind also often rely on the keyboard, since a mouse requires eye-hand coordination.

Keyboard accessibility is vital because it cuts across disability types and technologies. Most adaptive devices used by people with disabilities emulate the keyboard in terms of functionality. Content that is accessible to the keyboard is operable by the devices that emulate keyboard functionality, regardless of how they interface with the human user.

Interaction Methods

Users should be able to find, navigate, and interact with web content in multiple ways. Search features, site indexes, and site maps help users find content. Within web pages or sections of web content, users should be able to bypass repetitious content and focus on the content of interest to them. They should be able discern content structure using regions, headings, lists, and other elements of semantic structure.

While mobile devices are primarily controlled by touch interactions, they can support keyboards—if the mobile content or application does not break that support. Touch interactions should be made friendly to users that have limited motor abilities or control. Multipoint or path-based gestures, such as swiping across the screen to navigate, must be supplemented with single-touch controls, such as buttons, that provide the same functionality. Interactive controls in mobile content needs to be sufficiently large and separated from adjacent controls to avoid errant activation.

User Control Over Timing and Time Limits

Whenever possible, there should be no time limits on the web. Motor disabilities impact users' muscle movements. Cognitive disabilities impact their mental processes. Even visual or auditory disabilities can slow a person's response time if the information is not ideally accessible.

Practical exceptions exist, such as financial services (where timeouts protect users' information, especially in shared/public environments), academic testing (where a time limitation is part of the challenge), and auctions (where the hammer must eventually fall). In all cases, users should be allowed sufficient time to complete the tasks they are supposed to complete, whether by allowing everyone an unlimited amount of time, allowing special accommodations for those who need them, or some other solution between those two extremes.

Users should also be able to manipulate and control media players, animations, and any other kind of time-dependent content. Media players should include ways of pausing, rewinding, and fast-forwarding content. Users should be able to stop animations, since some users may find them so distracting that they cannot concentrate on the main content.

Flickering or strobing content that flashes three times or more per second or can trigger seizures and must be avoided.

Error Recovery

No one likes to accidentally delete a file, pay for the wrong product, send an email to the wrong person, or make any mistake that can't be corrected. Some people have disabilities that make them a little more likely to make a mistake. People with tremors may hit the wrong key or click on the wrong link. People with cognitive disabilities (or anyone else, for that matter) may misunderstand the purpose of a link and click the wrong one. People make spelling mistakes when typing search terms, their address, or any other kind of content.

Everyone appreciates the ability to recover from mistakes—to have a second chance. Confirmation pages, error alerts, and warnings should all be built into interactive web content. Even beyond this, it is often helpful to revisit the overall interaction design if the interface or process is so complicated that it seems to require a set of instructions. Basic usability techniques, such as breaking complicated tasks down into individual steps/pages, can help eliminate or at least decrease the number of errors committed by users in general.