All change for WCAG 2'0

1
All change for WCAG 2.0

• WHAT YOU NEED TO KNOW ABOUT THE NEW ACCESSIBILITY
  GUIDELINES

Patrick H. Lauke / Manchester Digital Development
Agency / 24 March 2009
2
About me...

• Web Editor for University of Salford
• Web Standards Project (WaSP)
• Author and occasional .net magazine contributor
• NOT an expert?

3
Outline

• Background on WCAG 1.0
• The painful birth of WCAG 2.0
• Overview of the new guidelines
• Next steps for WCAG 1.0 veterans

4
(No Transcript)
5
Web Content Accessibility Guidelines 1.0

• www.w3.org/TR/WCAG10
• W3C recommendation 5 May 1999
• 14 guidelines
• 75 checkpoints

6
WCAG 1.0 problems

• HTML-centric checkpoints, despite separate
  techniques document http//www.w3.org/TR/WAI-WEBCO
  NTENT-TECHS/
• until user agents clauses
• Forbids JavaScript and any non-W3C technologies
• Vague checkpoints

7
WCAG 2.0 early attempts

• Work began soon after release of WCAG 1.0
• Many iterations, largely under radar of web devs
• Original Last Call April 2006

8
(No Transcript)
9
To Hell with WCAG 2.0

• Joe Clark's vitriolic style
• A List Apart, 23 May 2006 http//www.alistapart.co
  m/articles/tohellwithwcag2
• Main points of concern
• Overall size of combined guidelines
• Inscrutable language
• Baseline concept
• Omission of markup validation / standards

10
To Hell with WCAG 2.0

• Generated huge interest from web devs
• Joe Clark started WCAG Samurai project to create
  errata for WCAG 1.0
• W3C demoted WCAG 2.0 from Last Call back to
  Public Working Draft

11
(No Transcript)
12
WCAG 2.0 back on track

• Joe Clark's leaving speech at _at_media2007
  confident that WCAG 2.0 heading in right
  direction
• Historical aside my take on amended WCAG 2.0
  http//www.webstandards.org/2007/06/11/review-wcag
  2-may2007-working-draft/
• Nonetheless released WCAG Samurai Errata
  http//wcagsamurai.org/

13
(No Transcript)
14
Web Content Accessibility Guidelines 2.0

• www.w3.org/TR/WCAG20
• W3C recommendation 11 December 2008

15
WCAG 2.0 suite of documents
16
WCAG 2.0 suite of documents

• Web Content Accessibility Guidelines 2.0
  normative
• How to Meet WCAG 2.0 informative
• Understanding WCAG 2.0 informative
• Techniques for WCAG 2.0 informative
• http//www.w3.org/WAI/intro/wcag20

17
Web Content Accessibility Guidelines 2.0

• 4 general principles
• 12 guidelines
• 61 success criteria

18
WCAG 2.0 principles

• A website should be...
• Perceivable
• Operable
• Usable
• Robust

19
WCAG 2.0 improvements

• Principles, guidelines and success criteria are
  technology-agnostic

20
WCAG 1.0 examples

• Guideline 5. Create tables that transform
  gracefully
• 5.3 Do not use tables for layout unless the
  table makes sense when linearized.
• Note. Once user agents support style sheet
  positioning, tables should not be used for
  layout.
• So what happens with CSS positioning that breaks
  linear flow?

21
WCAG 2.0 examples

• Guideline 1.3 Adaptable Create content that can
  be presented in different ways (for example
  simpler layout) without losing information or
  structure.
• 1.3.2 Meaningful Sequence When the sequence in
  which content is presented affects its meaning, a
  correct reading sequence can be programmatically
  determined.

22
WCAG 2.0 improvements

• WCAG 1.0 Guideline 11. Use W3C technologies and
  guidelines
• Where it is not possible to use a W3C
  technology, or doing so results in material that
  does not transform gracefully, provide an
  alternative version of the content that is
  accessible.
• WCAG 2.0 can be applied to W3C and non-W3C
  technologies (as long as they're
  accessibility-supported)

23
WCAG 2.0 improvements

• Accessibility-supported technologies
• supported by users' assistive technology
• technology must have accessibility-supported user
  agents that are available to users

24
WCAG 2.0 accessibility-supported

• You can use PDF, Flash, even JavaScript
• JavaScript and WAI-ARIA http//www.w3.org/TR/wai-a
  ria/
• Even if a technology isn't fully
  accessibility-supported, as long as you use the
  supported bits
• Worst case provide fallback that is supported

25
WCAG 2.0 improvements

• Removes all until user agents... clauses

26
WCAG 1.0 example

• Guideline 10. Use interim solutions.
• 10.4 Until user agents handle empty controls
  correctly, include default, place-holding
  characters in edit boxes and text areas.

27
WCAG 2.0 improvements

• Each success criterion is more easily testable
• Success criteria give clearer guidance than WCAG
  1.0 checkpoints

28
WCAG 1.0 example

• Guideline 2. Don't rely on color alone.
• 2.2 Ensure that foreground and background color
  combinations provide sufficient contrast when
  viewed by someone having color deficits or when
  viewed on a black and white screen.
• What exactly is sufficient?

29
WCAG 2.0 example

• Guideline 1.4 Distinguishable Make it easier
  for users to see and hear content including
  separating foreground from background.
• AA 1.4.3 Contrast (Minimum) The visual
  presentation of text and images of text has a
  contrast ratio of at least 4.51
• Large Text Large-scale text and images of
  large-scale text have a contrast ratio of at
  least 31
• AAA 1.4.6 Contrast (Enhanced) The visual
  presentation of text and images of text has a
  contrast ratio of at least 71
• Large Text Large-scale text and images of
  large-scale text have a contrast ratio of at
  least 4.51

30
WCAG 2.0 improvements

• As a result of clearer, testable SCs some things
  are allowed that previously weren't

31
WCAG 1.0 example

• Guideline 7. Ensure user control of
  time-sensitive content changes.
• 7.1 Until user agents allow users to control
  flickering, avoid causing the screen to flicker.
• 7.2 Until user agents allow users to control
  blinking, avoid causing content to blink...

32
WCAG 2.0 example

• Guideline 2.3 Seizures Do not design content in
  a way that is known to cause seizures
• 2.3.1 Three Flashes or Below Threshold Web
  pages do not contain anything that flashes more
  than three times in any one second period, or the
  flash is below the general flash and red flash
  thresholds.

33
WCAG 2.0 improvements

• Success criteria focus on the outcomes, not how
  they're achieved

34
WCAG 1.0 example

• Guideline 9. Design for device-independence.
• 9.5 Provide keyboard shortcuts to important
  links (including those in client-side image
  maps), form controls, and groups of form
  controls.
• For example, in HTML, specify shortcuts via the
  "accesskey" attribute.

35
WCAG 2.0 example

• Guideline 2.1 Keyboard Accessible Make all
  functionality available from a keyboard.
• 2.1.1 Keyboard All functionality of the content
  is operable through a keyboard interface ...

36
WCAG 2.0 improvements

• Talks about mechanisms
• process or technique for achieving a result

37
WCAG 2.0 mechanism example

• Guideline 2.4 Navigable Provide ways to help
  users navigate, find content, and determine where
  they are.
• 2.4.1 Bypass Blocks A mechanism is available to
  bypass blocks of content that are repeated on
  multiple Web pages.
• Does this mandate skip links?

38
WCAG 2.0 mechanism example

• Looking at How to meet WCAG 2.0, skip links
  only one of a few techniques mentioned
• Sufficient Techniques for 2.4.1 - Bypass Blocks
• Creating links to skip blocks of repeated
  material
• Grouping blocks of repeated material in a way
  that can be skipped
• Advisory Techniques for 2.4.1 - Bypass Blocks
• C6 Positioning content based on structural markup

39
WCAG 2.0 techniques

• Techniques cover general technologies HTML, CSS,
  JavaScript, WAI-ARIA
• Sufficient and advisory techniques
• Techniques are informative, not normative
• List of techniques is not exhaustive invent
  your own as long as success criteria are fulfilled

40
WCAG 2.0 conformance

• WCAG 1.0 had duality of priority 1,2,3 that
  mapped to levels A, AA, AAA
• WCAG 2.0 just uses A, AA, AAA model for both SCs
  and conformance levels

41
WCAG 2.0 conformance

• Applies to full pages
• Complete processes
• Only accessibility-supported techs are relied on
• Non-interference (when adding non-accessibility-su
  pported technologies)
• You can conform without a conformance claim

42
WCAG 2.0 partial conformance

• 3rd party content (UGC, feeds, etc)
• Use of languages/technologies without
  accessibility-support (future-proofing?)

43
Transition from WCAG 1.0 to WCAG 2.0

• Needs of users with disabilities hasn't changed
• Technology that they use has
• If your site accessible under WCAG 1.0, shouldn't
  be too far off WCAG 2.0

44
Transition from WCAG 1.0 to WCAG 2.0

• How WCAG 1.0 differs from WCAG 2.0
  http//www.w3.org/WAI/WCAG20/from10/diff.php
• Comparison WCAG 1.0 checkpoints to WCAG 2.0
  http//www.w3.org/WAI/WCAG20/from10/comparison/
• How to update your site from WCAG 1.0 to 2.0
  http//www.w3.org/WAI/WCAG20/from10/websites.html

45
Transition from WCAG 1.0 to WCAG 2.0

• Evaluate your site based on WCAG 2.0 SCs
• Many 1.0 checkpoints map to 2.0 SCs
• Are there 1.0 requirements that have been lifted?
• Test more specific 2.0 SCs

46
Getting started with WCAG 2.0

• WebAIM's unofficial checklist http//webaim.org/st
  andards/wcag/checklist

47
(No Transcript)
48
Getting started with WCAG 2.0

• For a one-stop shop overview, customisable WCAG
  2.0 quick reference http//www.w3.org/WAI/WCAG20/q
  uickref/

49
(No Transcript)
50
Recap on WCAG 2.0

• Technology-agnostic applicable to more present
  and future technologies
• Clearly testable Success Criteria
• Focussed on outcome for users, not techniques
• Removes outdated requirements from 1.0
• Overall allows authors more freedom

51
Thanks

• Patrick H. Lauke
• http//www.splintered.co.uk