Showing posts with label accessibility w3c wai wcag assitive technologies accessible. Show all posts
Showing posts with label accessibility w3c wai wcag assitive technologies accessible. Show all posts

November 24, 2007

People with Disabilities Using the Web

I have just read the W3C document How People with Disabilities Use the Web. It describes several scenarios, assistive technologies and possible barriers for user with disabilities. I will summarize the information here, removing the scenarios and the references. If anybody is interested I recommend reading the W3C document. The post will consist of several sections each dedicated for a disability with the respective assistive technology and barriers. The sections will follow the template

Disability:
Assistive technologies and strategies:

  • Assistive Technology 1
  • Assistive Technology 2
Barriers:
  • Barrier 1
  • Barrier 2
Blindness:
Assistive technologies and strategies:
  • screen readers
  • speech synthesizer
  • text-based browsers
  • voice browsers
Barriers:
  • images that do not have alternative text
  • complex images (e.g., graphs or charts) that are not adequately described
  • video that is not described in text or audio
  • tables that do not make sense when read serially (in a cell-by-cell or "linearized" mode)
  • frames that do not have "NOFRAME" alternatives, or that do not have meaningful names
  • forms that cannot be tabbed through in a logical sequence or that are poorly labelled
  • browsers and authoring tools that lack keyboard support for all commands
  • browsers and authoring tools that do not use standard applications programmer interfaces for the operating system they are based in
  • non-standard document formats that may be difficult for their screen reader to interpret
Low Vision:
Assistive technologies and strategies:
  • extra-large monitors
  • increasing the size of system fonts and images
  • screen magnifiers
  • screen enhancement software
  • specific combinations of text and background colors
Barriers:
  • absolute font sizes that do not change (enlarge or reduce) easily
  • inconsistent layout which makes navigation difficult the page is enlarged, due to loss of surrounding context
  • pages or images with poor contrast which cannot be easily changed through user override of author style sheets
  • text presented as images, which prevents wrapping to the next line when enlarged
  • many of the barriers listed for blindness
Color blindness:
Assistive technologies and strategies:
  • own style sheets to override the font and background color choices of the author
Barriers:
  • color that is used as a unique marker to emphasize text on a Web site
  • text that inadequately contrasts with background color or patterns
  • browsers that do not support user override of authors' style sheets
Deafness:
Remark: Deaf people may use predominantly a sign language, and they may or may not read a written language fluently, or speak clearly.

Assistive technologies and strategies:
  • captions for audio content
  • rely on supplemental images to highlight context.
Barriers:
  • lack of captions or transcripts of audio on the Web, including webcasts
  • lack of content-related images in pages full of text, which can slow comprehension for people whose first language may be a sign language instead of a written/spoken language
  • lack of clear and simple language
  • requirements for voice input on Web sites
Hard of hearing:
Assistive technologies and strategies:
  • captions for audio content
  • amplification of audio
Barriers:
  • lack of captions or transcripts for audio on the Web, including webcasts
Motor disabilities:
Remark: People with motor disabilities may need more time when filling out interactive forms on Web sites.

Assistive technolgoies and strategies:
  • specialized mouse
  • keyboard with a layout of keys that matches range of hand motion of the users
  • pointing device such as a head-mouse, head-pointer or mouth-stick
  • voice-recognition software
  • eye-gaze system
Barriers:
  • time-limited response options on Web pages
  • browsers and authoring tools that do not support keyboard alternatives for mouse commands
  • forms that cannot be tabbed through in a logical order
Speech disabilities:
Assistive techonolgies and strategies:
  • voice recognition software
  • alternate input mode such as text entered via a keyboard
Barriers:
  • voice-based interaction is required and no alternative input mode is available
Visual and auditory perception:
Assistive technologies and strategies:
  • getting information through several modalities at the same time (web site + screen reader, audio + captions)
Barriers:
  • lack of alternative modalities for information on Web sites, no textto be converted to audio to supplement visuals, no captions for audio
Attention deficit disorder:
Assistive technologies and strategies:
  • turn off animations
Barriers:
  • distracting visual or audio elements that cannot easily be turned off
  • lack of clear and consistent organization of Web sites
Intelectual disabilities:
Assistive technologies and strategies:
  • graphics to enhance understanding of a site
Barriers:
  • unnecessarily complex language on Web sites
  • lack of graphics on Web sites
  • lack of clear or consistent organization of Web sites
Memory disabilities:
Assistive technologies and strategies:
  • consistent navigational structure throughout the site
Barriers:
  • lack of clear or consistent organization of Web sites
Mental health disabilities:
Assistive technologies and strategies:
  • turning off distracting visual or audio elements
  • screen magnifiers
Barriers:
  • distracting visual or audio elements that cannot easily be turned off
  • Web pages with absolute font sizes that do not enlarge easily
Seizure disorders:
Assistive technologies and strategies:
  • turn off animations, blinking text, or certain frequencies of audio
Barriers:
  • use of visual or audio frequencies that can trigger seizures

Fore more detailed information, please visit How People with Disabilities Use the Web.