Web Content Accessibility Guidelines are part of a series of web accessibility guidelines
published by the Web Accessibility Initiative of the World Wide Web Consortium's, the main
international standards organization for the World Wide Web.
They consist of a set of guidelines for making content accessible, primarily for people with
disabilities, but also for all user agents, including highly limited devices, such as
mobile phones.
The current version, WCAG 2.0, was published in December 2008 and is also an ISO standard,
ISO/IEC 40500:2012.
Earlier guidelines The first web accessibility guideline was
compiled by Gregg Vanderheiden and released in January 1995 just after the 1994 Second
International Conference on the World-Wide Web in Chicago.
Over 38 different Web access guidelines followed from various authors and organizations over
the next few years.
These were brought together in the Unified Web Site Accessibility Guidelines compiled
by the at the University of Wisconsin-Madison.
Version 8 of the Unified Web Site Accessibility Guidelines, published in 1998, served as the
starting point for the W3C's WCAG 1.0.
WCAG 1.0 The WCAG 1.0 was published and became a W3C
recommendation on 5 May 1999.
They have since been superseded by WCAG 2.0.
WCAG 1.0 consist of 14 guidelines which are general principles of accessible design.
Each guideline covers a basic theme of web accessibility and is associated with one or
more checkpoints describing how to apply that guideline to particular features of webpages.
Guideline 1: Provide equivalent alternatives to auditory and visual content
Guideline 2: Don’t rely on colour alone Guideline 3: Use markup and style sheets,
and do so properly Guideline 4: Clarify natural language usage
Guideline 5: Create tables that transform gracefully
Guideline 6: Ensure that pages featuring new technologies transform gracefully
Guideline 7: Ensure user control of time sensitive content changes
Guideline 8: Ensure direct accessibility of embedded user interfaces
Guideline 9: Design for device independence Guideline 10: User interim solutions
Guideline 11: Use W3Ctechnologies and guidelines Guideline 12: Provide context and orientation
information Guideline 13: Provide clear navigation mechanisms
Guideline 14: Ensure that documents are clear and simple
Each of the in total 65 WCAG 1.0 checkpoints has a priority level assigned to it which
is based on the checkpoint's impact on accessibility: Priority 1: Web developers must satisfy these
requirements, otherwise it will be impossible for one or more groups to access the Web content.
Conformance to this level is described as A.
Priority 2: Web developers should satisfy these requirements, otherwise some groups
will find it difficult to access the Web content.
Conformance to this level is described as AA or Double-A.
Priority 3: Web developers may satisfy these requirements, in order to make it easier for
some groups to access the Web content.
Conformance to this level is described as AAA or Triple-A.
WCAG Samurai In February 2008, The WCAG Samurai, a group
of developers independent of the W3C, and led by Joe Clark, published corrections for,
and extensions to, the WCAG 1.0.
WCAG 2.0 WCAG 2.0 was published as a W3C Recommendation
on 11 December 2008.
It consists of 12 guidelines organized under 4 principles and each guideline has testable
success criteria.
Perceivable – Information and user interface components must be presentable to users in
ways they can perceive.
Guideline 1.1: Information and user interface components must be presentable to users in
ways they can perceive.
Guideline 1.2: Time-based Media: Provide alternatives for time-based media.
Guideline 1.3: Create content that can be presented in different ways without losing
information or structure.
Guideline 1.4: Make it easier for users to see and hear content including separating
foreground from background.
Operable – User interface components and navigation must be operable.
Guideline 2.1: Make all functionality available from a keyboard.
Guideline 2.2: Provide users enough time to read and use content.
Guideline 2.3: Do not design content in a way that is known to cause seizures.
Guideline 2.4: Provide ways to help users navigate, find content, and determine where
they are.
Understandable – Information and the operation of user interface must be understandable.
Guideline 3.1: Make text content readable and understandable.
Guideline 3.2: Make Web pages appear and operate in predictable ways.
Guideline 3.3: Help users avoid and correct mistakes.
Robust – Content must be robust enough that it can be interpreted reliably by a wide variety
of user agents, including assistive technologies.
Guideline 4.1.: Maximize compatibility with current and future user agents, including
assistive technologies.
WCAG 2.0 uses the same three levels of conformance as WCAG 1.0, but has redefined them.
The WCAG working group maintains an extensive list of web accessibility techniques and common
failure cases for WCAG 2.0.
Document history The first concept proposal of WCAG 2.0 was
published on 25 January 2001.
In the following years new versions were published intended to solicit feedback from accessibility
experts and members of the disability community.
On 27 April 2006 a "Last Call Working Draft" was published.
Due to the many amendments that were necessary, WCAG 2.0 was published again as a concept
proposal on 17 May 2007, followed by a second "Last Call Working Draft" on 11 December 2007.
In April 2008 the guidelines became a "Candidate Recommendation".
On 3 November 2008 the guidelines became a "Proposed Recommendation".
WCAG 2.0 as published as a W3C Recommendation on 11 December 2008.
In October 2012, WCAG 2.0 was accepted by the International Organization for Standardization
as an ISO International Standard, ISO/IEC 40500:2012.
The Web Accessibility Initiative is working on guidance for migrating from WCAG 1.0 to
WCAG 2.0.
A comparison of WCAG 1.0 checkpoints and WCAG 2.0 success criteria is available.
Legal obligations Businesses that have an online presence should
provide accessibility to disabled users.
Not only are there ethical and commercial justifications for implementing the Web Content
Accessibility Guidelines, there are also legal reasons.
If a business's website does not meet the Accessibility Guidelines, then the website
owner could be sued for discrimination.
On 27 January 2012, the Royal National Institute for the Blind in the United Kingdom issued
a press release stating that it had served legal proceedings against low-cost airline
bmibaby over their "failure to ensure web access for blind and partially sighted customers".
To date, at least two actions against websites have been initiated by the RNIB, and both
settled without the case being heard by a court.
Additionally, there has been one case of electronic accessibility that resulted in an employment
tribunal finding discrimination.
The case, against the Project Management Institute, was decided in October 2006, and the company
was ordered to pay compensation of £3,000.
The landmark 2010/2012 Jodhan decision has caused the Canadian Federal government to
require all online web pages, documents and videos available externally and internally
to meet the accessibility requirements of WCAG 2.0.
The Australian Government has also mandated via the Disability Discrimination Act 1992
that all Australian Government websites meet the WCAG accessibility requirements.
It is anticipated that higher-profile test cases will be launched against non-compliant
websites in the near future.
Since the law requires websites to take "reasonable steps" to make websites accessible to users,
it is anticipated that large companies will struggle to justify any failures to make their
websites accessible, while small businesses and charities may have a better defense, if
they can show that they do not have the resources necessary for the development work.
The Israeli Ministry of Justice recently published regulations requiring Internet websites to
comply with Israeli standard 5568, which is based on the W3C Web Content Accessibility
Guidelines 2.0.
The main differences between the Israeli standard and the W3C standard concern the requirements
to provide captions and texts for audio and video media.
The Israeli standards are somewhat more lenient, reflecting the current technical difficulties
in providing such captions and texts in Hebrew.
References
External links Web Content Accessibility Guidelines 1.0
Web Content Accessibility Guidelines 2.0 WAI Introduction to WCAG
WCAG 2.0 Tutorial WAVE – Online Accessibility validator
WCAG 2.0 checklist Achieving WCAG 2.0 with PDF/UA – Document
published by the Association for Information and Image Management