accessibility in a web 2.0 world
DESCRIPTION
Accessibility in a Web 2.0 World. (get a straw). Shawn Henry, W3C WAI. Topics. Components ATAG WCAG 2.0 Dynamic applications Scripting, AJAX, RIA (rich Internet applications) Handouts: Expanded version Additional URIs. You ?. W3C WAI ? WCAG 1.0 ? WCAG 2.0 ? ATAG ? Screen readers ? - PowerPoint PPT PresentationTRANSCRIPT
Topics
ComponentsATAG
WCAG 2.0
Dynamic applicationsScripting, AJAX, RIA (rich Internet applications)
Handouts:Expanded version
Additional URIs
W3C WAI
World Wide Web Consortium (W3C)International
Develops Web standards (HTML, CSS, …)
Web Accessibility Initiative (WAI)Develops Web accessibility guidelines,
international standards
www.w3.org/WAI/
ACTION !
Actively encourage improvements in authoring tools
WAI resources:
Authoring Tool Accessibility Guidelines (ATAG)
Selecting and Using Authoring Tools for Web Accessibility
What’s New with WCAG TwoApplies to more advanced Web
technologies
More precisely testable (still need human)
Adaptable for situations (Baseline)
Extensive supporting materials, practical implementation
WCAG 1.0
Guidelines
CheckpointsPriority 1, 2, 3
WCAG 2.0 Principles
Guidelines
Success CriteriaLevel 1, 2, 3
Testable, Levels Example WCAG 1.0 Checkpoint
2.2 Ensure that foreground and background color combinations provide sufficient contrast when viewed by someone having color deficits…
WCAG 2.0 Success Criteria 1.4.1 Text or diagrams, and their background,
have a luminosity contrast ratio of at least 5:1 [Level 2]
1.4.3 Text or diagrams, and their background, have a luminosity contrast ratio of at least 10:1 [Level 3]
[Level 2]
WCAG 2.0 Supporting DocumentsOverview of WCAG 2.0 Documents
Techniques for WCAG 2.0 WD
WCAG 2.0 Quick Reference WD Understanding WCAG 2.0 WD
Coming• How to make accessible tables, forms, …
• Quick Tips …
• UI
When?
Public Working Drafts
Last Call Working Draft
Candidate RecommendationImplementations
Proposed Recommendation
W3C Recommendation=Web Standard
Transitioning
Most sites that conform to WCAG 1.0 should not require significant changes
See WCAG 2 FAQ
Support: "How WCAG 2.0 Drafts Differ from WCAG 1.0"
section
Comparison of WCAG 1.0 Checkpoints to WCAG 2.0
Transitioning Web Sites
Transitioning Accessibility Policies
Understanding Baseline
First, WhyFlexibility for different situations today
Flexibility over time
For example, SVG (Scalable Vector Graphics)
WCAG Working Group is refining(expect some changes)
BaselineList of technologies
For example: HTML, CSS, etc...That are accessible, that users have available
An established list of Web technologies that an author can use to create accessible Web content
Can use technologies outside of baseline, if content is usable withoutThat is, used for enhancement
Topics
Components ATAG
WCAG 2.0 Baseline
Dynamic applications• Scripting, AJAX, RIA
(coming up: additional slides since handout)
Scripting Tips for Accessibility Do automatic redirects on server side,
instead of client side Device independence, e.g.,
onmouseover & onfocus mousedown & keydown click & keypress mouseover & focus mouseout & blur
Techniques for WCAG 2.0“Client-side Scripting Techniques”
AJAX
Accessibility
Usability – general, for allUser doesn’t know updates will happen auto
User doesn’t notice updates
User can’t find updated info
Unexpected change in focus
Back button breaks
Can’t bookmark
AJAX Temperature Gauge
Not just cool, hot? Really useful to users?
ApproachDISCLAIMER: not endorse, others too, …
the hows and whys of degradable ajax
Progressive enhancement with Ajax “first build your app using old-fashioned server-
side technology… once you’ve got that built, you can then apply JavaScript…”
“progressive enhancement [is] how we should all be building our web apps” – Jeremy Keith
AJAX
Accessibility
Usability – general, for allUser doesn’t know updates will happen auto
User doesn’t notice updates
User can’t find updated info
Unexpected change in focus
Back button breaks
Can’t bookmark
Straw Activity
Some people have a very small field of vision -- called “tunnel vision”. Imagine using a complex Web page like this…
AJAX
AccessibilityUser doesn’t know updates will happen
auto
User doesn’t notice updates
User can’t find updated info
Unexpected change in focus – can’t read page
Back button breaks
Can’t bookmark
Whaddyado for Now
Explain interaction
Provide options (default least problematic!)Manual update
Notifications (e.g., dialog box)
Draw attention (e.g., “yellow fade technique”)
Set focus
Avoid automatic focus change (usually)
…
More Whaddyado for Now
…
<Hx> and proper markup
Provide navigation to changes
Example:The DOM and Screen Readers(Juicystudio) Errors from Form Validation DISCLAIMER: not endorse, others too,…
Whaddyado for Later
ARIA Suite for Accessible Rich Internet Appsfrom W3C WAI Protocols & Formats WG
Some implementations already
Accessibility for Dynamic ApplicationsCreate desktop-style widgets for Web
e.g., tree control
Keyboard nav (w/o excessive Tab)(benefit keyboard “power” users)
Notification of updates
Dynamic Applications
•DISCLAIMER: not endorse, others too,…AJAX Accessibility Overview, Becky Gibson, IBM
+W3C Announces Roadmap for Accessible Rich Internet Applications (WAI-ARIA) press release
+Call for Review: Accessible Rich Internet Applications (WAI-ARIA) Working Drafts e-mail
+ARIA Overview (coming soon)
+www.w3.org/WAI/ Highlights
And so
WCAG 2.OBetter for developers
Better accessibility
Dynamic ApplicationsBe a showcase: Get attention, get help