wcag 2.0, simplified
DESCRIPTION
Basic info to begin understanding the new WCAG 2.0 Guidelines from the W3C WAI committee.TRANSCRIPT
WCAG, Simplified
What is it and what do I have to do?
Topics
• What is WCAG? Is it a law?• Changes from WCAG 1 to
version 2• Examples• Accessibility vs. Usability• Easy First Steps• WCAG 2.0 Basics
What is WCAG?
Guidelines vs. Laws
Country Laws
• Australia• Canada• Denmark• European Union• Finland• France• Germany• Hong Kong• India• Ireland• Israel
• Italy• Japan• New Zealand• Portugal• Spain• Switzerland• United Kingdom• United States of
America
USA
• Section 255 of the Telecommunications Act• Rehabilitation Act, Section 504• Rehabilitation Act Amendments of 1998,
Section 508• Americans with Disabilities Act (ADA)• Individuals with Disabilities Education Act
(IDEA) • New Freedom Initiative + State Lawshttp://www.webaim.org/articles/laws/usa/
Example: Kentucky
• Additional Kentucky state laws regarding accessibility of digital content– AIT – Accessible Information Technology
Statute stating state information, technology, equipment and software must be accessible to employees and the general public.
– Textbook Act – publishers must provide an accessible digital version within 15 days of request.
What is WCAG?
Web Content Accessibility Guidelineswww.w3.org/TR/WCAG20/
• Other WAI Guidelines– ATAG - Authoring Tool Accessibility
Guidelines– EARL - Evaluation and Report
Language– UAAG - User Agent Accessibility
Guidelines – WAI ARIA - Accessible Rich Internet
Applications Suite
• The World Wide Web Consortium (W3C) is an international consortium where Member organizations, a full-time staff, and the public work together to develop Web standards. W3C's mission is: To lead the World Wide Web to its full potential by developing protocols and guidelines that ensure long-term growth for the Web.
• WAI, in coordination with organizations around the world, pursues accessibility of the Web through four primary areas of work: technology, tools, education and outreach, and research and development.
Who develops WCAG?
• The W3C Web Accessibility Initiative (WAI) develops...
• guidelines widely regarded as the international standard for Web accessibility
• support materials to help understand and implement Web accessibility
• resources, through international collaboration
– WAI welcomes...• participation from around the world (price prohibitive)• volunteers to review, implement, and promote guidelines• dedicated participants in working groups
Who develops WCAG?
The WCAG guidelines are widely regarded as the voluntary international
standard for web accessibility
Technology Changes
In 1999…• HTML, PDF,
Javascript
• Static, information pages
• Desktop, laptop
• IE, Netscape
In 2009…• XHTML, CSS, Flash,
PDF, Javascript, AJAX
• Dynamic, interactive, social networking
• + phones, pdas, gps, car, tv, fridge…
• + Opera, Safari, Firefox…
Changes in WCAG 2.0
Adding testable criteria, principles, and understanding
What WCAG 2 gives you
• International standard, developed cooperatively
• Applies to more advanced Web technologies– current, future, non-W3C
• Clearer criteria, more precisely testable• Adaptable, flexible for different situations,
and developing technologies and techniques
• Extensive supporting materials, practical implementation guidance
Technology neutral
WCAG 1 – Checkpoint 3.4Use relative rather than absolute units in markup language attribute values and style sheet property values.
WCAG 2 – Success Criterion 1.4.4Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality.
WCAG 1.0 – WCAG 2.0
WCAG 1.0 WCAG 2.0 Principles: P-O-U-
R
Guidelines Guidelines
CheckpointsPriority 1, 2, 3
Success CriteriaLevel A, AA, AAA
Support Support
Techniques Techniques
Understanding
Flexibility for Audience
Scripting allowed
• Back in 1999, screen readers and other assistive technology did not support scripting.
• Scripted websites were inaccessible under Perceivable and Operable Principles.
• Now major browsers and assistive technologies support scripting and it can be used to enhance accessibility if the proper techniques are used.
Examples
CAPTCHAs, Animation, etc.
More design flexibility
• WCAG 1.0– 7.1 Until user agents allow users to control
flickering, avoid causing the screen to flicker.
• WCAG 2.0 allows more movement within defined parameters (for instance)– Three Flashes or Below Threshold:
2.3.1 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. (Level A)
Example - CAPTCHA
• CAPTCHA notes– Providing more than two modalities of CAPTCHAs– Providing access to a human customer service
representative who can bypass CAPTCHA– Not requiring CAPTCHAs for authorized users
Example: Contrast
• WCAG 1.0 Checkpoint– 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.
• WCAG 2.0 Success Criteria– 1.4.3 Contrast (Minimum): The visual
presentation of text and images of text has a contrast ratio of at least 5:1, except for the following:•Large Text: Large-scale text and images of large-scale text
have a contrast ratio of at least 3:1;• Incidental: Text or images of text that are part of an
inactive user interface component, that are pure decoration, that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement.
•Logotypes: Text that is part of a logo or brand name has no minimum contrast requirement.
(from the Dec 2008 Draft)
Example: Contrast
Example: Navigation
• WCAG 1 - Provide clear and consistent navigation mechanisms -- orientation information, navigation bars, a site map, etc. -- to increase the likelihood that a person will find what they are looking for at a site.
• WCAG 2 - Provide ways to help users navigate, find content and determine where they are.– 2.4.1 Bypass Blocks– 2.4.2 Page Titled– 2.4.3 Focus Order– 2.4.4 Link Purpose
Exception Example
• Text Alternatives: Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language.– Non-text Content: All non-text content that is presented
to the user has a text alternative that serves the equivalent purpose, except for the situations listed below.
• Controls, Input (function rather than description)• Time-Based Media (streams of live events)• Test (art history test)• Sensory (no alternative text exists, however, it can be
described)• CAPTCHA (security)• Decoration, Formatting, Invisible (not content)
CAPTCHA Notes
• If you must use CAPTCHAs– Provide more than two modalities of
CAPTCHAs– Provide access to a human customer service
representative who can bypass CAPTCHA– Do not require CAPTCHAs for authorized
users
Sufficient Technique Example
WCAG 2 – Success Criterion 1.4.4 [Resize text]Sufficient Technique example
• Ensuring that text containers resize when the text resizes AND using measurements that are relative to other measurements in the content by using one or more of the following techniques:– Techniques for relative measurements
• C12: Using percent for font sizes (CSS) • C13: Using named font sizes (CSS) • C14: Using em units for font sizes (CSS)
– Techniques for text container resizing• Calculating size and position in a way that scales with
text size (Scripting) • G146: Using liquid layout
Accessibility vs. Usability
Your website can be accessible yet unusable
Accessibility ≠ Usability
• A website can comply with standards.• A website can pass all the automated
accessibility checks.• A website can appear to be accessible.
HOWEVER
• An accessible website is not necessarily usable.• Web pages can be verified accessible by focus
groups, and still be inaccessible to a third party.• Individual users may have cognitive, technical,
or other barriers.
Assume failure by someone
• Offer content in alternative formats• Provide phone, email, and other contact
information
Closure…
WCAG 2.0
• More generic
• More testable
• Doesn’t claim to meet everyone’s need
• May need to be supplemented with other guidelines/standards/advisory techniques, and laws
• User testing is still important
Understand your users, the technologies, and where these guidelines fit into the toolbox.
Easy First Steps
You have already begun!
Fix the easy stuff first
• Alt text• Alternative formats• Correctly labeled links• Best practices for web development (Usability)
– Simplify pages (language, design, navigation)– Resizable, clear font face– Reduce links, and link throughs (three click rule)– Consistent navigation– Contact info– Quick loading pages– Verify code, hyperlinks, spelling, CSS
Other Commons Sense Ideas
• Use templates• Policy to respond quickly to complaints• Give contact info for complaints• Disability statements• Use checklists or automated checkers
WGAC 2.0 Basics
Digging in to the Guidelines
WCAG 2.0 Quick Ref
Guidance Hypertext
• Principles - POUR• Guidelines - Under the POUR principles are
twelve basic goals to make content more accessible.
• Success Criteria - For each Guideline, testable success criteria are provided. Conformance is defined by A (lowest), AA, and AAA (highest).
• Sufficient and Advisory Techniques - For each of the Guidelines and Success Criteria, documentation includes techniques and explanations on why the guideline is necessary.
Hypertext Document
POUR Principles
• Perceivable• Operable• Understandable• Robust
POUR Principles
• Perceivable– Provide text alternatives for any
non-text content– Provide alternatives for time-
based media– Separate content from style– Make it easier for users to see
and hear content
• Operable– Make all functionality available from
a keyboard– Provide users enough time to read
and use content– Do not design content known to
cause seizures– Provide ways to help users navigate,
find content and determine where they are
POUR Principles
• Understandable– Simplify text content– Web pages operate in
predictable ways– Help users avoid and correct
mistakes
POUR Principles
• Robust– Maximize compatibility with
other products, including assistive technologies.
POUR Principles
12 Guidelines Under POUR
1. Text Alternatives
2. Time Based Media
3. Adaptable4. Distinguishable5. Keyboard
Accessible6. Enough Time
7. Seizures8. Navigable9. Readable10.Predictable11.Input Assistance12.Compatible
Success Criteria
Sufficient Technique
s
Advisory Technique
s
Failures
Source Material
www.w3.org/TR/WCAG20/ www.w3.org/WAI/www.WebAim.org www.w3.org/WAI/Resources/Overviewwww.uiaccess.com/understanding.htmlwww.w3.org/WAI/presentations/
WCAG20_about/
Parker Owens, [email protected] Kentucky University, USA, 2009
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