Designing for accessibility means accepting that, for web sites, there is:
- No standard user (information consumer/person) using the web
- No standard device for browsing the web
People to Consider:
- People with Visual Disabilities
- People with Mobility/Motor/Dexterity Disabilities
- People who are Deaf or Hard of Hearing
- People with Cognitive Disabilities
Gain an appreciation of web accessibility through the following video "Introduction to Web Accessibility and W3C Standards".
1. People with Visual Disabilities
- Blind - unable to see visual information
- Euteranopia - red-green deficiency
- Protanopia - red deficiency
- Tritanopia - blue/yellow deficiency
- Achromatopsia - total color blindness
- Low vision (can see but not well; may need large fonts or magnifiers). Far-sightedness, and other vision impairments greatly increase after the age of forty.
People who are blind usually navigates using only the keyboard and use screen readers, braille displays, voice input, and/or screen magnifiers. Among the needs of this group is meaningful text equivalents so a screen reader can "read" the information. Examples of how to provide accessible content for people with visual disabilites include using alt attributes for images and audio description for video.
People who have color disabilities may have the inability to distinguish the differences between certain colors, so they may need higher contrast to distinguish colors and alternative ways of identifying colored content.
2. People with Mobility/Motor/Dexterity Disabilities
People with Mobility/Motor/Dexterity disabilities have difficulty moving one or more parts of the body. Where web design and development is concerned, this usually involves a disability involving the hands and/or arms. It can include:
- Total or partial paralysis
- Repetitive stress injuries (RSI)
- ALS (Arterial Lateral Sclerosis; Lou Gehrig's Disease)
- Parkinson's disease
- Spinal cord injuries
- Cerebral palsy
- Loss of limbs or digits
- Low dexterity (unable to use a pointing device like a mouse and instead must use keyboard or switch)
This group may experience difficulties using the mouse or the keyboard. The assistive technologies that people with motor disabilities include alternate input (e.g. voice) and keyboard alternatives (switch, sip and puff, etc).
3. People Who are Deaf or Hard of Hearing
- Deaf - people with profound hearing losses
- Hard of Hearing - people who cannot hear sounds reliably
Assistive technology that this group utilizes include captioning and transcripts.
Note: The phrase "hearing impaired" is typically rejected by members of the Deaf Community as it negatively emphasizes deficiency. People who use sign language generally refer to themselves as deaf. In some cases, the word Deaf is spelled with a capital D to refer to members of the Deaf Community.
4. People with Learning Difficulties and/or Cognitive Disabilities
- Attention Deficit Disorder
- Low comprehension (having problems understanding content, textual or otherwise)
- Low reading (having problems reading text)
- Other non-verbal learning difficulties
- Loss of brain function
- Short term memory loss
- Epilepsy - may be subject to epileptic episodes
- Alzheimer's disease
- Parkinson's disease
- Multiple sclerosis
Cognitive disabilities impact the ability to access, process or remember information; and limits the ability to perceive, recognize, understand, interpret or respond to information. The assistive technologies that this group uses include word prediction aids, reading/writing comprehension aids.
Others Who Benefit From Accessible Web Sites Include People Who:
- Access content in a situation where their eyes, ears, or hands are busy (e.g. driving to work, working in a noisy environment)
- Use technology such as mobile phones
- Surf the web using text-based browser such as Lynx
- Do not load images for various reasons
- Are annoyed or distracted by flashing animations
Have hardware limitations such as:
- Small screens
- Older computers or browser versions
- No audio speakers
Terminology: Words Matter
How we write and talk about disability affects the way we view people with disabilities. Inappropriate language can often be offensive and dis-empowering. Use appropriate and respectful language that is neutral, accurate, and represents the preference of the groups to which it refers. This will help convey integrity and respect. Consult the following for more information:
- Accessible Writing Guide - Anna Cavender , Shari Trewin, and Vicki Hanson, ACM’s Special Interest Group on Accessible Computing.
Terms to Avoid When Writing About Disability - National Center on Disability and Journalism
- Style Guide - National Center on Disability and Journalism