Accessibility issues for web authors

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Accessibility issues for web authors

• Library and Information Services
• University of St Andrews

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Structure

1. Definition Accessibility
2. Legal requirement
3. How people access the web
4. Web Accessibility Initiative
5. Checking your web pages
6. Resources

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1. Definition Accessibility

• Technical aspects
• hard- software issues
• different devices
• internet connection
• Varying individual needs
• people with disabilities
• use of specialised software

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2. Legal requirement

• SENDA (2001) and DDA (1995)
• Responsible bodies must not treat a disabled
  person less favourably than a non-disabled person
  for reasons related to their disability without
  justification
• Responsible bodies will be required by law to
  make reasonable adjustments to ensure that a
  disabled person is not placed at a substantial
  disadvantage.

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3. How people access the web

• Visual disabilities
• Blindness, colour blindness, other visual
  impairments
• Physical disabilities
• Repetitive stress injury
• Hearing disabilities
• Deafness, hard of hearing
• Cognitive disabilities
• Dyslexia, attention deficit disorder,
  intellectual impairments
• Neurological disabilities
• Seizure disorders, mental health problems
• among others.

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3.1. Visual disabilities
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3.1.1. Blindness

• Specialised software
• Speech synthesisers, braille browsers
• Text-based browsers (Lynx)
• Possible use of rapid browsing techniques
• Potential problems include
• Images without descriptive alt tags
• Tables that do not make sense when read serially,
  i.e. in a linearised way
• Navigational features that rely on mouse, no
  keyboard navigation
• Hyperlinks dont use meaningful text
• Non-standard document formats

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Use meaningful text for hyperlinks (1/2)

• For more information on how to get to Paris,
  please click here.
• Click here to download a map of the city centre.
• To look at the 2003 statistics on tourism to
  France, click here.

is turned into ...
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Use meaningful text for hyperlinks (2/2)

• click here
• Click here
• 
  
  
  
  
  
• 
  click here

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Use descriptive ALT tags

• Context 1 as a simple graphic of an
  organisations logo appearing on a web page.
• altASPC logo
• Context 2 image is active link to the home page
  of a web site.
• altHome
• Context 3 image might be used in a list of
  properties, as an icon to indicate properties
  available through the ASPC. Since the image
  contains an abbreviation, the alt text of the
  image might now be
• altArdcalloch Solicitors Property Centre

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Lynx

• Example web sites
• http//www.polarfle.com
• http//arts.st-andrews.ac.uk
• Online lynx viewer
• http//www.delorie.com/web/lynxview.html

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3.1.2. Colour blindness

• Lack of sensitivity to certain colours
• Possible use of personalised style sheets
• Potential problems include
• Colour that is used as a unique marker to
  emphasise text
• E.g. click the red button

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• Potential problems (cont.)
• Inadequate contrast between text and background
• Certain colour combinations
• No option to override default colours

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Examples of colour deficits

• Protanope
• one out of 100 males, red-weakness
• Deuteranope
• five out of 100 males, green-weakness
• Tritanope
• blue/yellow deficit

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Colour perception (1/2)
Normal vision
Protanope
Deuteranope
Tritanope
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Colour perception (1/2)
Normal vision
Protanope
Deuteranope
Tritanope
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Other visual impairments

• Forms include poor acuity, tunnel vision,
  central field loss, clouded vision
• Specialised software
• Screen magnifyers, speech synthesisers
• Possible use of grayscale display

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• Potential problems include
• Absolute font sizes
• Inability to change colour settings
• Inconsistent layout that makes navigation
  difficult
• Centred display of items on screen
• Poor contrast
• Text presented as images
• Resolution of images conveying important
  information is too low
• Depending on type and extend of disability, many
  of the problems blind people encounter

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3.2. Physical disabilities
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3.2.1. Repetitive stress injury

• Happens when too much stress is placed on a
  joint same action is performed over and over
  again
• Possible use of software that does not require
  the use of a mouse
• Potential problems include
• Web pages cannot be navigated using a keyboard
  alone

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3.3. Hearing disabilities
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3.3.1. Deafness

• Sign language may be first language, i.e.
  possible problems reading written language
  fluently
• Potential problems include
• Lack of captions or transcriptions of audio
  content
• Lack of content-related images
• Lack of clear and simple language

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3.3.2. Hard of hearing

• People with mild or moderate hearing impairments
• Possible problems include
• Lack of captions or transcripts for audio content

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3.4. Cognitive disabilities
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3.4.1. Dyslexia

• Possible difficulty processing written language
  or images when read visually, or spoken language
  when heard, or numbers when read visually or
  heard
• Possible use of speech synthesisers
• Possible problems include
• Lack of alternative text that can be converted to
  audio to supplement visuals
• Justified text
• Mixture of fonts font sizes

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• Possible problems (cont.)
• Extensive use of ALL CAPS
• Words split across lines
• Large chunks of text
• No white space between paragraphs

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3.4.2. Attention deficit disorder

• Difficulty focusing on information
• Possible problems include
• Distracting visual or audio elements that cannot
  be turned off
• Lack of clear and consistent organisation of web
  sites

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3.4.3. Intellectual impairments

• May learn more slowly, difficulty understand
  complex concepts
• Possible problems include
• Use of unnecessarily complex language
• Lack of graphics
• Lack of clear and consistent organisation

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3.5. Neurological disabilities
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3.5.1. Seizure disorders

• E.g. photosensitive epilepsy
• Avoid content that flickers at a frequency of
  between 2 and 59Hz
• Possible problems
• Animated, flickering or flashing content

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3.5.2. Mental health problems

• May have difficulty focusing on information,
  experience blurred vision or hand tremors owing
  to side effects of medication
• Possible problems include
• Distracting audio or visual elements that cannot
  be turned off
• Use of absolute font sizes

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3.6. Complexities

• Multiple disabilities
• e.g. deaf blind
• Conflicting needs of people with different
  disabilities
• e.g. People with cognitive disabilities may
  require graphical rather than textual
  presentation blind people rely on text.
• You cant get it right for everyone. Therefore,
  make sure that people can override your settings!

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4. The Web Accessibility Initiative (WAI)

• http//www.w3.org/WAI/
• Guidelines
• Web Content Accessibility Guidelines 1.0 (WCAG
  1.0, http//www.w3.org/TR/WCAG)
• Authoring Tool Accessibility Guidelines 1.0
• User Agent Accessibility Guidelines 1.0

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Web Content Accessibility Guidelines 1.0

• 3 Priorities (Levels of compliance)
• Priority 1 (A-compliant)
• Criteria a web developer must satisfy
• Basic requirement for some groups to be able to
  access web documents
• Priority 2 (AA-compliant)
• Criteria a web developer should satisfy
• Removes significant barriers to accessing web
  documents
• Priority 3 (AAA-compliant)
• Criteria a web developer may satisfy
• Improves access to web documents

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5. Checking your web pages

• Use validators
• HTML validator http//validator.w3.org
• Bobby http//bobby.watchfire.com/bobby/html/en/in
  dex.jsp
• Cynthia SaysTM http//www.cynthiasays.com/Default
  .asp
• Apply visual checks
• Use of colours
• Use of fonts (font-family, relative sizes, )
• Meaningful ALT tags
• Check your web pages in various browsers

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6. Resources

• Vischeck Colour vision simulator
  http//www.vischeck.com/examples/
• W3C validators and technical standardshttp//ww
  w.w3.org
• Teachability http//www.Teachability.strath.ac.uk
  
• Techdis http//www.techdis.ac.uk
• SENDA/DDAhttp//www.legislation.hmso.gov.uk/acts/
  acts2001/20010010.htm
• JISC legalhttp//www.jisclegal.ac.uk/publications
  /legalimplicationsDDA.htm
• and many more

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Accessibility issues for web authors

• Library and Information Services
• University of St Andrews