Accessibility issues for web authors

1. Accessibility issues for web authors Library and Information Services University of St Andrews

2. Structure • Definition: Accessibility • Legal requirement • How people access the web • Web Accessibility Initiative • Checking your web pages • Resources

3. 1. Definition: Accessibility • Technical aspects • hard- & software issues • different devices • internet connection • Varying individual needs • people with disabilities • use of specialised software

4. 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.

5. 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.

6. 3.1. Visual disabilities

7. 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 don’t use meaningful text • Non-standard document formats

8. 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 ...

9. Use meaningful text for hyperlinks (2/2) • click here • Click here • click here

10. Use descriptive ALT tags Context 1: as a simple graphic of an organisation’s logo appearing on a web page. alt=“ASPC logo” Context 2: image is active link to the home page of a web site. alt=“Home” 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 alt=“Ardcalloch Solicitor’s Property Centre”

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

12. 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”

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

14. Examples of colour deficits • Protanope • one out of 100 males, “red-weakness” • Deuteranope • five out of 100 males, “green-weakness” • Tritanope • blue/yellow deficit

15. Colour perception (1/2) Normal vision Protanope Deuteranope Tritanope

16. Colour perception (1/2) Normal vision Protanope Deuteranope Tritanope

17. 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

18. 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

19. 3.2. Physical disabilities

20. 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

21. 3.3. Hearing disabilities

22. 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

23. 3.3.2. Hard of hearing • People with mild or moderate hearing impairments • Possible problems include: • Lack of captions or transcripts for audio content

24. 3.4. Cognitive disabilities

25. 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

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

27. 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

28. 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

29. 3.5. Neurological disabilities

30. 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

31. 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

32. 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 can’t get it right for everyone. Therefore, make sure that people can override your settings!

33. 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

34. 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

35. 5. Checking your web pages • Use validators: • HTML validator: http://validator.w3.org • Bobby: http://bobby.watchfire.com/bobby/html/en/index.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

36. 6. Resources • Vischeck Colour vision simulator:http://www.vischeck.com/examples/ • W3C: validators and technical standards:http://www.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

37. Accessibility issues for web authors Library and Information Services University of St Andrews