Evaluating Cognitive Web Accessibility
A few important points:
- There are many types of cognitive and learning disabilities and an even wider variety of needs and capabilities of users who have these disabilities.
- This population is larger than those with all other physical and sensory disabilities combined.
- Because needs vary across these disabilities, it's difficult to make definitive recommendations that will universally help all users with cognitive and learning disabilities. Despite this, there is much we can do that is beneficial.
- Beyond research that WebAIM and others have conducted, there is much insight that can be drawn from learning sciences, usability, and other areas of web accessibility.
- Improving web accessibility for this audience will improve access for everyone.
Principles of Cognitive Web Accessibility
Cognitive accessibility can be defined by the following principles:
In many ways, it's hard to define when a page is "accessible" to users with cognitive disabilities. How simple is simple enough? For the most part, cognitive web accessibility is one of those "you know it when you see it" things. Common sense, holistic evaluation, and user testing should predominantly guide cognitive web accessibility evaluation.
Cognitive Web Accessibility Checklist
The following checklist attempts to address the principles above (though do not map directly to them) and can serve as a guide for improving cognitive web accessibility. These recommendations are based on a combination of internal and existing research, common best practices, and thoughtful speculation.
Assistive Technology Compatibility
Users with cognitive or learning disabilities often use screen readers, text-to-speech systems, or other assistive technologies to access content through various senses or to modify content to be best perceivable to them. Users with cognitive or learning disabilities have a higher prevalence of other physical or sensory disabilities. Many assistive technology issues are addressed in the Web Content Accessibility Guidelines (WCAG) and include (but are not limited to):
- Ensure that navigation is consistent throughout a site
Navigation placement, display, and functionality should not change from page to page.
- Similar interface elements and similar interactions should produce predictably similar results
- Support text adaptations
The page should remain readable and functional when text is increased 200-300% or when text spacing is adjusted.
- Ensure images are readable and understandable when enlarged
Content within images, particularly text, should be understandable when the image is scaled 200-300%. Use true text instead of text within images when feasible.
- Ensure color alone is not used to convey information
- Support the disabling of images and/or styles
Ensure that the page remains readable and functional when images are disabled (alternative text will be displayed instead) or when styles are disabled.
- Provide content in multiple mediums
Video or audio alternatives provide an additional method of perceiving media content. Captions should be provided for multimedia content, and transcript provided for all multimedia and audio content. Closed captioning, which gives users the option to turn off the captions, is optimal.
- Use images to enhance content
Images can be used to convey or enhance content. Illustrations, diagrams, icons, and animations can convey complex information.
- Pair icons or graphics with text to provide contextual cues and help with content comprehension
Focus and Structure
- Use white space and visual design elements to focus user attention
The design of a page (white space, color, images, etc.) should focus the user on what is most important (typically the body content of that page). White space can draw visual focus and separate page content areas.
- Avoid distractions
Animation or auto-playing video, varying or unusual font faces, highly contrasting color or images, or other distracters that pull attention away from content should be avoided. Complex or "busy" background images can draw attention away from the content. Be careful with pop-up windows and blinking or moving content.
- Use stylistic differences to highlight important content, but do so conservatively
Use various stylistic elements (italics, bold, color, brief animation, or differently-styled content) to highlight important content. Overuse can result in the loss of differentiation. Do not use italics or bold on long sections of text. Be careful with ALL CAPS.
- Organize content into well-defined groups or chunks, using headings, lists, and other mechanisms
Break long pages into shorter sections with appropriate headings (use true and visually significant headings rather than simply big bold text). Very long pages may be divided into multiple, sequenced pages. Unordered, ordered, and definition lists provide a visual structuring and convey semantic meaning (e.g., an unordered list conveys a group of parallel items). Use shorter, multi-step forms for complex interactions, rather than lengthy, complex forms.
- Avoid background sounds
Give the user control over playing audio content within the page or, at a minimum, give the user control to stop the background sounds.
Readability and Language
- Use language that is as simple as is appropriate for the content and audience
- Avoid tangential, extraneous, or non-relevant information
Stick to the content at hand.
- Use correct grammar and spelling
Use a spell-checker. Write clearly and simply.
- Maintain a reading level that is adequate for the audience
Readability tests can be performed on the body text (for accuracy, do not include web site navigation, side bar, footer, or other extraneous text elements in the evaluation). Generally, web content should be understandable by those with a lower secondary education, though an elementary reading level may be necessary for some users with certain cognitive or learning disabilities. More complex content may require diligence in implementing other items in this checklist.
- Be careful with colloquialisms, non-literal text, and jargon
- Expand abbreviations and acronyms
Provide the full meaning in text at the first occurrence.
- Provide summaries, introductions, glossaries, and/or a table of contents for complex or lengthy content
- Be succinct
Provide the minimum amount of text necessary to convey the content.
- Ensure text readability
- Line height
The amount of space between lines should generally be no less than half the character height.
- Line length
Very long lines of text are more difficult to read.
- Letter spacing, word spacing, and justification
Provide appropriate (but not too much) letter and word spacing. Avoid full justified text as it results in variable spacing between words and can result in distracting "rivers of white" - patterns of white spaces that flow downward through body text.
- Adequate text size
Text should generally be at least 10 pixels in size.
- Content appropriate fonts
Visually appealing and content-appropriate fonts affect satisfaction, readability, and comprehension.
- Paragraph length
Keep paragraph length short.
- Adequate color contrast
Ensure text is easily discerned against the background and that links are easily differentiable from surrounding text.
- No horizontal scrolling
Avoid horizontal scrolling when the text size is increased and when the page is enlarged.
- Line height
Orientation and Error Prevention/Recovery
- Give users control over time sensitive content changes
Avoid automatic refreshes or redirects. Allow users to control content updates or changes. Avoid unnecessary time-outs or expirations. Allow users to request more time.
- Provide adequate instructions and cues for forms
Ensure required elements and formatting requirements are identified. Provide associated and descriptive form labels and fieldsets/legends.
- Give users clear and accessible form error messages and provide mechanisms for resolving form errors and resubmitting the form
- Give feedback on a user's actions
Confirm correct choices and alert users to errors or possible errors.
- Provide instructions for unfamiliar or complex interfaces
- Use breadcrumbs, indicators, or cues to indicate location or progress
Allow users to quickly determine where they are at in the structure of a web site (e.g., a currently active "tab" or Home > Products > Widget, for example) or within a sequence (Step 2 of 4). Next/Previous options should be provided for sequential tasks.
- Allow critical functions to be confirmed and/or canceled/reversed
- Provide adequately-sized clickable targets and ensure functional elements appear clickable
Use labels for form elements, particularly small checkboxes and radio buttons, and ensure all clickable elements appear clickable and do not require exactness.
- Use underline for links only
- Provide multiple methods for finding content
A logical navigation, search functionality, index, site map, table of contents, links within body text, supplementary or related links section, etc. all provide multiple ways for users to find content.
Funding for this material provided by the Office of Special Education and Rehabilitative Services Steppingstones of Technology Innovation Grant #H327A070057.