Accessibility

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Accessibility

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What is accessibility?

• "The power of the Web is in its universality.
  Access by everyone regardless of disability is an
  essential aspect." -- Tim Berners-Lee, W3C
  Director and inventor of the World Wide Web
• For a multimedia application to be accessible,
  its content must be available to everyone,
  including people with disabilities.
• Type accessibility in a web browseryou will see
  the results you get..

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What is Accessibility?

• Smooth transformation information and services
  should be accessible despite physical, sensory or
  cognitive user disabilities, work constraints or
  technological barriers
• Understandable and navigable content content
  should be presented in a clear and simple manner,
  and should provide understandable mechanisms to
  navigate within and between pages.
• Content
• can be perceived
• can be navigated
• can be utilised (with keyboard or devices other
  than mice)
• can be easily understood (even in attention-poor
  situations)

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The Human Factor

• 10 to 20 of the population in most countries
  have a disability
• Not all of those disabilities affect access to
  the Web
• Vision, hearing, mobility and cognitive problems
  do affect access
• Average age of population in many countries is
  increasing
• Vision hearing degrades, changes in dexterity
  memory
• Some of us become temporarily disabled due to
  accident or illness

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Web Accessibility Initiative

• Set By W3
• Sets guidelines for general web accessibility but
  also applies to accessibility in general
• How do we make things accessible?
• Where can we look for more information on
  accessibility?
• Full page - http//www.w3.org/WAI/
• Quick Tips - http//www.w3.org/WAI/References/Quic
  kTips/
• Full checklist - http//www.w3.org/TR/WCAG10/full-
  checklist.html and http//www.w3.org/WAI/gettingst
  arted/
• How they view the web - http//www.w3.org/WAI/EO/D
  rafts/PWD-Use-Web/

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Why do it?

• A proportion of your audience is disabled
• That should be enough reason why.
• UK
• http//news.zdnet.co.uk/story/0,,t269-s2105208,00.
  html
• http//www2.warwick.ac.uk/fac/soc/law/elj/jilt/200
  0_1/chung/
• http//www.drc-gb.org/
• America Section 508
• http//www.section508.gov

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BUT

• Nine in ten of the UK's top companies are failing
  to make their Web sites accessible to people with
  disabilities.
• http//www.theregister.co.uk/2004/01/20/disabled_u
  sers_struggle_to_access/
• http//www.webcredible.co.uk/user-friendly-resourc
  es/web-accessibility/

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Accessibility Means Dull

• WRONG!!!!!!
• An accessible application is NOT dull, plain
  boring text
• WAI guidelines tell you how to do things
  accessibly, they dont say Dont do it
• Accessibility is not about restricting your
  multimedia/graphical design it's about enhancing
  it!

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Quick Tips

• Images animations Use the alt attribute to
  describe the function of each visual.
• Multimedia. Provide captioning and transcripts of
  audio, and descriptions of video.
• Hypertext links. Use text that makes sense when
  read out of context. For example, avoid "click
  here."
• Page organization. Use headings, lists, and
  consistent structure.
• Graphs charts. Summarise
• Allow the user to personalise

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Disability Guidelines
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Visual impairments

• Three main groups
• Blind
• Low vision (poor visual acuity, tunnel vision,
  etc.)
• Colour blind (_at_ 10 of male population)
• Red/green
• Blue/yellow
• No colour perception

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Technologies Used

• Screen readers (JAWS, WindowEyes, Home Page
  Reader)
• Braille readers
• Text browsers directing content to speech
  synthesizers
• Screen magnifiers (ZoomText and others)
• Large monitors, low resolution (lt 640x480)
• Personalise (font sizes colour combinations)

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Assistive technologies

• Braille readershttp//www.humanware.com/
• JAWShttp//www.freedomscientific.com/
• Home Page Readerhttp//www.spectronicsinoz.com/pr
  oduct.asp?product3997
• Zoomtexthttp//www.aisquared.com/index.cfm

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Problems for blind people

• 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 "linearised" mode)
• Document formats that may be difficult for screen
  readers to interpret

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Text

• Provide a text equivalent for every non-text
  element This includes images, graphical
  representations of text (including symbols),
  image map regions, animations (e.g., animated
  GIFs), applets and programmatic objects, ascii
  art, frames, scripts, images used as list
  bullets, spacers, graphical buttons, sounds
  (played with or without user interaction),
  stand-alone audio files, audio tracks of video,
  and video

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Does the text help the blind user?
The text is not an equivalent of the graphical
information An equivalent might be Map showing
the location of Monash campuses together with a
long description indicating distance from and
relative location to the city
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Examples of text equivalents
Look at your page in a text browser to get an
idea of how to write text equivalents
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Barriers for people with low vision

• Absolute font sizes that do not change (enlarge
  or reduce) easily
• Inconsistent layouts, are difficult to navigate
  when enlarged due to loss of surrounding context
• Poor contrast, and contrast that cannot be easily
  changed through user override
• Also some of the barriers listed for blindness

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Colour Blindness
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Colour Blindness

• http//www.vischeck.com/

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Barriers for people with colour blindness

• Meaning that is conveyed by colour alone
• Colour that is used as a unique marker to
  emphasise text
• Text that inadequately contrasts with background
  colour or patterns
• Solution - Ensure that all information conveyed
  with colour is also available without colour, for
  example from context or markup

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Examples of use of colour alone
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Which is more accessible to blind or visually
impaired people?
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Hearing Impairments

• Deafness
• Deaf community is a linguistic community
• First language is sign language
• Hard of hearing

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Barriers for people with hearing impairments

• Use of long sentences, uncommon or sophisticated
  vocabulary
• Lack of captions or transcripts of audio
• 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

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Seizures

• Seizure disorders
• Triggered by visual flickering or audio signals
  at a certain frequency
• People with seizure disorders may need to turn
  off animations, blinking text, or certain
  frequencies of audio

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Photosensitive Epilepsy

• allow users to control flickering, avoid causing
  the screen to flicker
• allow users to control blinking, avoid causing
  content to blink
• allow users to freeze moving content, avoid
  movement in pages
• People with photosensitive epilepsy can have
  seizures triggered by flickering or flashing in
  the 4 to 59 flashes per second (Hertz) range with
  a peak sensitivity at 20 flashes per second as
  well as quick changes from dark to light (like
  strobe lights).
• http//www.epilepsy.org.uk/info/photo_web.html

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Other Considerations

• Cognitive impairments
• Dyslexia
• Dyscalculia
• Difficulty processing written or spoken language,
  or numbers when read visually or heard
• May rely on getting information in several ways
  at the same time (e.g. pictures / animation and
  text)
• Provide alt text that can be converted to audio
  to supplement visuals
• Dont use unnecessarily complex language
• Complex sentence structures
• Use of long words or sophisticated language

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Quasi-Disabilities

• These conditions create similar experience
• Low spec PCs
• Missing Plug-ins
• No Speakers
• Small Display
• Eyes Busy/Hands Busy
• Noisy Environment

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Macromedia And Accessibility

• http//www.adobe.com/accessibility/
• Director - http//www.adobe.com/macromedia/accessi
  bility/features/director/

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Tools

• Aprompt - http//aprompt.snow.utoronto.ca/
• Betsie - http//www.bbc.co.uk/education/betsie/
• Vischeck - http//www.vischeck.com/
• Free accessibility Test - http//www.usablenet.com
  /
• WAVE - http//wave.webaim.org/index.jsp
• Lynx Viewer
• http//www.delorie.com/web/lynxview.html
• Might be useful for HCI section of projects

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Other stuff

• http//www.rnib.org.uk/xpedio/groups/public/docume
  nts/code/public_rnib008789.hcsp
• http//www.w3.org/WAI/wcag-curric/
• http//ncam.wgbh.org/webaccess/magpie/
• Beyond ALT Tag - http//webpac.staffs.ac.uk8080/i
  nternal/beyond_alt_text.pdf
• Accessibility Design - http//webpac.staffs.ac.uk
  8080/internal/accessibility_methodology.pdf
• http//www.nomensa.com/resources/articles/
• http//www.usabilitynews.com/news/article1321.asp
• http//www.usabilitynews.com/news/article1274.asp
• http//www.mardiros.net/accessible-web-design.html
  
• http//directory.google.com/Top/Computers/Software
  /Internet/Clients/WWW/Browsers/Accessibility/
• http//www.webaim.org/
• http//www-3.ibm.com/able/guidelines/web/accessweb
  .html
• http//trace.wisc.edu/world/web/
• http//www.nfb.org/tech/webacc.htm
• http//library.uwsp.edu/aschmetz/Accessible/websur
  veys_p.htm
• http//hotwired.lycos.com/webmonkey/99/20/index0a.
  html?twdesign