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Web Accessibility - an introduction Patrick H. Lauke PowerPoint Presentation
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Web Accessibility - an introduction Patrick H. Lauke

Web Accessibility - an introduction Patrick H. Lauke

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Web Accessibility - an introduction Patrick H. Lauke

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  1. Web Accessibility - an introductionPatrick H. Lauke ISI presentation - 15/12/2005

  2. Introduction What we’ll cover today: • some of the misconceptions about accessibility • reasons why accessibility is important • highlight some web accessibility guidelines Q&A at the end, but please shout out any questions.

  3. So why am I here? • involved in web since early 90s • University webmaster since 2001 • responsible for writing and enforcing web strategy, standards and guidelines for UoS • involved in global discourse on accessibility • WaSP (Web Standards Project) Accessibility Task Force

  4. Some misconceptions What is accessibility? “making sure our web site works for the blind…” There is a wide range of disabilities: • visual impairments • auditory impairments • mobility impairments • cognitive disabilities

  5. Some misconceptions Why bother? Marketing executive: “such a small market is not worth the hassle” Web designer: “no time to create a separate accessible site” Site owner: “blind people won’t be using my web site”

  6. Some misconceptions Marketing executive: “such a small market is not worth the hassle” It is estimated that there are 7 million disabled people in the UK and that around 19% of the working age population has some form of disability. Source: Disability Rights Commission – Disability briefing January 2004

  7. Some misconceptions Web designer: “no time to create a separate accessible site” In majority of cases, no need for special “disabled only access” site. • Inclusive design, not segregation • Separation of content and presentation, using web standards, structural markup: single site, accessible to all • Accessibility included in planning stage, not as an afterthought • “Text only” is not a solution

  8. Some misconceptions Site owner: “blind people won’t be using my web site” Accessibility not just about the blind, but… A possible scenario: visually impaired customer buying photographs or paintings for a sighted relative?

  9. Legal requirements If the ethical / moral and financial reasons were not enough, there are legal requirements: • UK - Disability Discrimination Act 1995provision of goods and services • Australia – Disability Discrimination Act 1992 • USA – Americans with Disabilities Act • USA – Section 508 of Rehabilitation Actprocurement policy for federal government agencies Other countries have similar legislation. Cases are being brought to court: SOCOG, RNIB, Ramada/Priceline…

  10. Access for all More importantly • Accessibility is not just about users with disabilities • Provisions and changes made for accessibility can benefit all users “Real world” example: access ramps With regards to web: • Benefits to users of alternative browsing devices (PDAs, web phones, etc) • Not a permanent disability, but “situational” – library PC, loud environment, etc Crossover between usability and accessibility

  11. Accessibility and SEO Google and co. world’s largest “disabled users”

  12. W3C Guidelines So…what’s a web designer to do? World Wide Web Consortium (W3C) committed to 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 W3C Web Accessibility Initiative (WAI) produced Web Content Accessibility Guidelines (WCAG)

  13. W3C Guidelines WCAG 1.0, 5 May 1999 14 guidelines (general principles), broken down into checkpoints. Checkpoints categorised into 3 priority levels • [Priority 1] A Web content developer must satisfy this checkpoint. • [Priority 2] A Web content developer should satisfy this checkpoint. • [Priority 3] A Web content developer may address this checkpoint.

  14. W3C Guidelines • Provide equivalent alternatives to auditory and visual content. • Don't rely on color alone. • Use markup and style sheets and do so properly. • Clarify natural language usage • Create tables that transform gracefully. • Ensure that pages featuring new technologies transform gracefully. • Ensure user control of time-sensitive content changes. • Ensure direct accessibility of embedded user interfaces. • Design for device-independence. • Use interim solutions. • Use W3C technologies and guidelines. • Provide context and orientation information. • Provide clear navigation mechanisms. • Ensure that documents are clear and simple. Not going to go through all, but give a few examples

  15. WCAG examples 1) Provide equivalent alternatives to auditory and visual content. ALTernate text for images

  16. WCAG examples 1) Provide equivalent alternatives to auditory and visual content. Captions and transcripts for audio/video files http://www.splintered.co.uk/experiments/66/

  17. WCAG examples 2) Don’t rely on color alone Coloured buttons without any additional information

  18. WCAG examples 2) Don’t rely on color alone Coloured links surrounded by normal text

  19. WCAG examples 3) Use markup and style sheets and do so properly. <p><font size=“+3”><b>This is a heading</b></font></p> <p>Blah blah blah</p> <p><font size=“+3”><b>This is another heading</b></font></p> <p>Blah blah blah</p> <p><font size=“+2”><b>A sub-section</b></font></p> <p>Blah blah blah</p>

  20. WCAG examples 3) Use markup and style sheets and do so properly (cont.) <h1>This is a heading</h1> <p>Blah blah blah</p> <h1>This is another heading</h1> <p>Blah blah blah</p> <h2>A sub-section</h2> <p>Blah blah blah</p> • Machine-readable. • Convey meaning and structure, not just visual appearance. • Cfr MS Word and screen readers. • “But the headings look ugly…” – use CSS • Outline: • This is a heading • This is another heading • A sub-section

  21. WCAG examples 6) Ensure that pages featuring new technologies transform gracefully • Plugin technologies: Java, Flash, Shockwave. • Scripting: VBScript (IE only!), reliance on javascript. Worst case: navigation or other essential page feature.

  22. WCAG examples 6) Ensure that pages featuring new technologies transform gracefully Javascript popups – what happens when JS is off/unavailable? <a href=“#” onclick=“window.open(‘foo.html’)”>bar</a> Can be made accessible (fallback mechanism): <a href=“foo.html” onclick=“window.open(this.href); return false;”>bar</a>

  23. WCAG examples 9) Design for device-independence • Mouse • Keyboard • Voice activation • Switches • Headwands Don’t rely on mouse, e.g. onmouseover/onmouseout javascript event handlers. Choose device-independent alternatives instead: onfocus/onblur

  24. WCAG examples 9) Design for device-independence Ensure sensible tab order (links, form elements, etc)

  25. WCAG examples …and many, many more.

  26. Automated validators The infamous “Bobby”…(now WebXact http://webxact.watchfire.com/ ) • Automated accessibility checkers are dumb. • “Bobby” and co. are just a tool and do not replace human checks. • False positives, false negatives.See:http://www.isolani.co.uk/blog/access/SiteMorseFailsDueDiligence All my images have an ALTernate text of “image”…is that accessible?

  27. Conclusion Hopefully, what you’ll take away from this presentation: • Accessiblity not just about “the blind” • Moral, financial and legal reasons to ensure web sites are accessible • Accessibility can benefit all users • W3C WAI WCAG and some examples Worth noting: accessibility not about rote mastery of a few guidelines. Many cases where there is no one single solution – requires judgement and compromise.

  28. Word of warning? Want to do web design/development as a job? Essential skills – not just an option: • Web standards (semantic/structural markup, CSS) • Accessibility (beyond “Bobby”)

  29. Resources • W3C Web Accessibility Initiativehttp://www.w3.org/WAI/ • Accessifyhttp://www.accessify.com/ • Accessifyforumhttp://www.accessifyforum.com/ • WebAIM: Web Accessibility In Mindhttp://www.webaim.org/ • Isolanihttp://www.isolani.co.uk/ • Dive into Accessibilityhttp://www.diveintoaccessibility.org/ • “Evaluating Web Sites for Accessibility with the Firefox Web Developer Toolbar”http://www.webaim.org/techniques/articles/evaluatingwithfirefox • WaSP (Web Standards Project)http://webstandards.org