Transcript EDU_web_accessibilit..

Web Accessibility - an introduction
Patrick H. Lauke
Date
or reference
EDU
briefing session - 7/2/2006
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.
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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
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Some misconceptions
What is accessibility?
“making sure our web site works for the blind…”
There is a wide range of disabilities:
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visual impairments
auditory impairments
mobility impairments
cognitive disabilities
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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”
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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
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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
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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?
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Legal requirements
If the ethical / moral and financial reasons were not enough, there are
legal requirements:
• UK - Disability Discrimination Act 1995
provision of goods and services
• Australia – Disability Discrimination Act 1992
• USA – Americans with Disabilities Act
• USA – Section 508 of Rehabilitation Act
procurement policy for federal government agencies
Other countries have similar legislation.
Cases are being brought to court: SOCOG, RNIB,
Ramada/Priceline…
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Legal requirements for Education
Original Disability Discrimination Act 1995 eplicitly excluded
Public Transport and Education
Special Educational Needs and Disability Act 2001 (SENDA)
removed exemption, effectively became part IV of the DDA.
“Disabled students not to be substantially disadvantaged”
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Access for all
More importantly
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Accessibility is not just about users with disabilities
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Provisions and changes made for accessibility can benefit all users
“Real world” example: access ramps
With regards to web:
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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
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Accessibility and SEO
Google and co.
world’s largest “disabled users”
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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)
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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.
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W3C Guidelines
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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
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WCAG examples
1) Provide equivalent alternatives to auditory and visual content.
ALTernate text for images
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WCAG examples
1) Provide equivalent alternatives to auditory and visual content.
Captions and transcripts for audio/video files
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http://www.splintered.co.uk/experiments/66/
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WCAG examples
2) Don’t rely on color alone
Coloured buttons without any additional information
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WCAG examples
2) Don’t rely on color alone
Coloured links surrounded by normal text
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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>
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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>
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Outline:
•This is a heading
•This is another heading
–A sub-section
Machine-readable.
Convey meaning and structure, not just visual appearance.
Cfr MS Word and screen readers.
“But the headings look ugly…” – use CSS
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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.
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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>
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WCAG examples
9) Design for device-independence
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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
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WCAG examples
9) Design for device-independence
Ensure sensible tab order (links, form elements, etc)
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WCAG examples
…and many, many more.
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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?
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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.
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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”)
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Resources
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W3C Web Accessibility Initiative
http://www.w3.org/WAI/
Accessify
http://www.accessify.com/
Accessifyforum
http://www.accessifyforum.com/
WebAIM: Web Accessibility In Mind
http://www.webaim.org/
Isolani
http://www.isolani.co.uk/
Dive into Accessibility
http://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
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