Visual Impairments and Accessibility

According to Nielsen (1996) visual impairments cause the most serious accessibility issues.  Visual impairments are of many types such as complete blindness, partially sighted, etc.  Regardless of the impairment type, the total population of people with visual impairments is predicted to be increasing rapidly at a rate of 2 million per year worldwide (WHO, 2002).  When determining how disability affects accessibility, blind people are considered to be “unable to “see,” or rather access a web page, if they are not provided with assistance in the form of a screen reader or an audible web client. Although these aids are useful, their application is somewhat limited. The use of graphics without necessary guides or aids results in a page being inaccessible to the visually impaired community. Given that a vast majority of web sites are designed to be visual, nearly 50 million people are then automatically excluded (WHO 2001).  According to W3C, people with blindness will encounter a number of barriers in using the web which include:
  • Images that do not have ‘alt’ 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 linear fashion)
  • 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 labeled
  • 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
The problems summarized by the W3C underline the severity of the challenge facing the blind. Their access to web-based information can be impaired in any number of ways. Oftentimes, access is simply impossible. On the other hand, the people with low vision, often known as partially impaired, experience certain barriers in browsing the web, which are also audited by W3.
  • Web pages with absolute font sizes, i.e. that do not enlarge or reduce easily
  • Web pages that, because of inconsistent layout, are difficult to navigate when enlarged, due to loss of surrounding context
  • Web pages, or images on Web pages, that have poor contrast, and whose contrast cannot be easily changed through user override of author style sheets
  • Imaged text that cannot be re-wrapped
  • Also many of the barriers listed for blindness, above, depending on the type and extent of visual limitation
Hence, all visually-impaired people experience some difficulty with accessing web-based information. While blind people may have greater difficulty than those who are partially sighted, the problems are similar. A lack of consistency in web design is a key problem along with the highly visual nature of most web pages (Good, 2008).

Mobility Impairments and Accessibility

People with physical or motor impairments may experience some difficulty accessing the web; however, these disabilities often manifest themselves differently than visual impairments. First, it is essential to distinguish between the disabilities which cause inaccessibility to websites. Arguably, a person with a wheelchair is classified as mobility impaired but does not necessarily experience difficulty accessing the web. However, people with dexterity impairments, either as a result of a neurological disorder or arthritis (Emiliani, 2001), are affected. In general, problems consist of difficulties in manipulating the mouse or performing precise movements with a tracking pad. An inability to use the keyboard might also exist, in particular holding down two or more keys simultaneously. According to Nielsen (1996), ten years ago image maps were the main cause of access difficulties simply because they required such precision in usage. Since this time, page navigation has become increasingly complex with buttons and links becoming smaller and requiring a greater degree of precision and motor skills (Hackett et al, 2003). There are a number of other problems this group may face. Motor disabilities manifest themselves in a variety of ways. The W3C gives the following examples of the problems that people in this category may experience in accessing web-based information:
  • 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 (Note: "Tabindex" solution not yet well supported in browsers)
Hence, as is the case in almost every category, users with motor disabilities suffer from the lack of consistency in web design. In addition, some features of web pages fail to allow for different response times. Eichhorn et al (2008) emphasizes more sophisticated understandings of differential needs and appropriate sources as the most crucial step in enabling disabled tourists to access tourism information. Along with the influence of other barriers that individuals with mobility impairments may face, poor web design will also have a strong impact. For example users may find it difficult to use the ecommerce site due to the need of making precise mouse movements, small links, fixed fonts, poor contrast between foreground and background colors, etc. Hence, these issues have to be taken into consideration at the design phase.

Reference

http://eprints.port.ac.uk/4129/1/Microsoft_Word_-_Sambhanthan_et_al_Accessibility.pdf http://www.useit.com/alertbox/20011111.html http://www.w3.org/TR/WCAG20/ Note: The Topic Accessibility Standards has been adapted by Arunasalam Sambhanthan

Hearing Impairment and Accessibility

Just as images aren't available to people who can't see, audio files aren't available to people who can't hear. Providing a text transcript makes the audio information accessible to people who are deaf or hard of hearing, as well as to search engines and other technologies that can't hear (W3C 2005). Although individuals with a hearing impairment may not experience any difficulty accessing or navigating through websites, they may face barriers to accessing other online material including:
  • Audio
  • Video
  • Multi-media
Offering a text transcript of podcasts, videos or other audio files makes this information accessible to people with a hearing impairment. Options to make sure that all of your audio and video files are accessible to everyone include:
  • Captioning
  • Transcripts
  • Sign Language Videos
Google has a beta transcriber coming out with mixed reviews. Free video captioning is available from MAGpie (Media Access Generator) and can be downloaded from the National Center for Accessible Media’s website. Prior to applying captioning or transcripts to your website make certain to notify users that the content includes captioning. Include a precise set of instructions on accessing the transcripts or captioning with the audio or video file.  Remember to include the file size of the video since some users may review the script before downloading the video clip. A service to translate your video into American Sign Language is available at deaflink.com.

Cognitive Impairment and Accessibility

Individuals with a cognitive impairment such as Down Syndrome, Autism Spectrum Disorder or Attention Deficit Hyperactive Disorder may not face any barriers in physically seeing the content or navigating with a regular mouse and keyboard. The barrier these individuals may face is the actual content itself. Web designers may face some challenges when creating accessible and usable websites for users with cognitive disabilities. “Persons with learning disabilities often have trouble processing language and numbers, deciphering auditory input, and with spatial orientation” (W3C 2005). Using good web design practice and common sense can help to make sure your content is presented in a clear manner. Some suggestions for making pages easier to follow and understand are:
  • Use plain language in short and easy-to-understand sentences
  • Create structured pages using clear headings and information hierarchy
  • Break complex processes into smaller steps (use a step-by-step wizard)
  • Provide supplemental media (video, illustrations, etc.) to describe complex processes or ideas
  • Prioritize information and make sure the most important material is “above the fold,” at the top half of the page
  • “Chunk” relevant information together in paragraphs, conveying one idea per paragraph
  • Use bulleted lists whenever possible to eliminate long paragraphs of information

 Hearing Impairment and Accessibility

Just as images aren't available to people who can't see, audio files aren't available to people who can't hear. Providing a text transcript makes the audio information accessible to people who are deaf or hard of hearing, as well as to search engines and other technologies that can't hear (W3C 2005). Although individuals with a hearing impairment may not experience any difficulty accessing or navigating through websites, they may face barriers to accessing other online material including:
  • Audio
  • Video
  • Multi-media
Offering a text transcript of podcasts, videos or other audio files makes this information accessible to people with a hearing impairment. Options to make sure that all of your audio and video files are accessible to everyone include:
  • Captioning
  • Transcripts
  • Sign Language Videos
Google has a beta transcriber coming out with mixed reviews. Free video captioning is available from MAGpie (Media Access Generator) and can be downloaded from the National Center for Accessible Media’s website. Prior to applying captioning or transcripts to your website make certain to notify users that the content includes captioning. Include a precise set of instructions on accessing the transcripts or captioning with the audio or video file.  Remember to include the file size of the video since some users may review the script before downloading the video clip. A service to translate your video into American Sign Language is available at deaflink.com.

References

"Accessibility of State and Local Government Websites to People with Disabilities." Accessibility of State and Local Government Websites to People with Disabilities. United States Government, n.d. Web. 18 Feb. 2013. <http://www.ada.gov/websites2.htm>. This website explains the importance of complying websites with the Americans with Disabilities Act and has links to section 508 of the Act. "HTML Writers Guild Web Accessibility Standards." Policy: Web Accessibility Standards. HTML Writers Guild, n.d. Web. 21 Feb. 2013. <http://www.hwg.org/opcenter/policy/access.html>. This websites lists the twelve accessibility features of guild websites, including providing text equivalent for non text elements and making sure pages are usable without style sheets. "Information Technology and People with Disabilities: The Current State of Federal Accessibility." US Dept. of Justice, n.d. Web. 19 Feb. 2013. <http://www.justice.gov/crt/508/report/content.php>. This website includes the accessibility standards that all federal agency's webpages must comply with to meet accessibility requirements. Although not all websites are required to meet these standards, they are useful to reference for all websites. Nielson, Jakob. "Nielsen Norman Group." Beyond Accessibility: Treating Users with Disabilities as People. N.p., n.d. Web. 15 Feb. 2013. <http://www.nngroup.com/articles/beyond-accessibility-treating-users-with-disabilities-as-people/>. This article discusses usability testing with three groups of people: a screen reader using group, a screen magnifier group and a control group with no disabilities. The study found that usability is three times better with non-disabled users. "Web Content Accessibility Guidelines (WCAG) 2.0." Web Content Accessibility Guidelines (WCAG) 2.0. N.p., n.d. Web. 20 Feb. 2013. <http://www.w3.org/TR/WCAG20/>. These are complete guidelines for making web content accessible to the disabled; this includes the visually, hearing, physically and cognitively impaired. The guidelines are followed to make web content more perceivable, operable, understandable and robust to every user.