- Guidelines are more specific, e.g. specifying contrast ratio or time-based actions in seconds.
- Success Criteria are written in a technology neutral fashion.
- Success Criteria are written as testable statements.
- Gathering 'implementation experience' is now part of the W3C Process.
- Guidelines include requirements related to informing users of data entry errors.
But what I personally like the best is the revamped structure called layers of guidance:
The WCAG 2.0 define a logical hierarchy of accessibility guidelines called layers of guidance. All of these layers work together to provide guidance on how to make content more accessible.
The foundation is built on four principles that are essential for anyone to access and use Web content, i.e. every Web content must be:
These principles are the four pillars of Web accessibility and describe at a high level what can be done to assist users with varying needs to successfully access your content.
The 12 guidelines are basic goals that authors of Web content should work toward in order to create accessible content. None of them are testable and are only meant as a framework of overall objectives. The guidelines are:
- 1.1 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.
- 1.2 Provide alternatives for time-based media.
- 1.3 Create content that can be presented in different ways (for example simpler layout) without losing information or structure.
- 1.4 Make it easier for users to see and hear content including separating foreground from background.
- 2.1 Make all functionality available from a keyboard.
- 2.2 Provide users enough time to read and use content.
- 2.3 Do not design content in a way that is known to cause seizures.
- 2.4 Provide ways to help users navigate, find content, and determine where they are.
- 3.1 Make text content readable and understandable.
- 3.2 Make Web pages appear and operate in predictable ways.
- 3.3 Help users avoid and correct mistakes.
- 4.1 Maximize compatibility with current and future user agents, including assistive technologies.
Now, the success criteria is where the meat is. For each Guideline, testable success criteria are provided. Every Web content or series of Web content (complete web page or series of connected pages) can be tested and evaluated against these criteria and further assigned a true/false (equals pass or fail) value.
These success criteria are further divided into three levels of conformance, meaning satisfying all the requirements of a given standard, guideline or specification:
- Level A (lowest; minimum level of conformance)
- Level AA
- Level AAA (highest)
The notion of conformance is so important that I will discuss it in a separate blog entry.
Sufficient and Advisory Techniques
Up until now all the principles, guidelines, and success criteria are written in a technology neutral fashion. That's great but what now? The Working Group has identified and published examples for HTML implementations that should serve as examples and tutorials and are kept in the living document called Techniques for WCAG 2.0. This document explains a variety of techniques on how to implement the given guideline for each success criteria. The list is not complete and will be expanded as new techniques are discovered.
The techniques fall into two categories:
- Sufficient techniques: considered to be sufficient to meet a success criteria.
- Advisory techniques: enhance accessibility, but did not qualify as sufficient techniques.
Most Success Criteria have multiple sufficient techniques listed. Any of the listed sufficient techniques can be used to meet the Success Criterion. Also there may be other techniques which are not documented by the working group that could also meet the Success Criterion. This is especially true for content that is not HTML.
Resume & Criticism
I'm really excited about the WCAG 2.0, their clear structure and promising, almost marketing-like wording. I also like the amount of effort taken to document examples, techniques and common failures.
What I miss is the programmer perspective that outlines each element with its associated success criteria and code samples, e.g. how can I make tables accessible, what about links, captcha, maps, etc.? I think this work is up to us and I will continue to tackle this issue by grouping, summarizing and compiling elements so I can publish them on this blog.
What are your opinions on WCAG 2.0?
So you know what Accessibility is and how it improves your ROI and why everybody benefits. Now what exactly is Section 508 and how does it correlate with W3C's Web Content Accessibility Guidelines (WCAG 1.0)? And most important, how can you create an accessible.htm that complies with these standards?
Overview: WCAG & Section 508
The main institutions involved (as shown in the illustration above) are:
- GSA (U.S. General Services Administration) represented by the IT Accessibility and Workforce (ITAW) who is the governments principal advocate and coordinator for Section 508 implementation. Other agencies and organizations may offer similar information, but ITAW is recognized as the governmentwide policy resource for Section 508.
- World Wide Web Consortium (W3C) represented by the Web Accessibility Initiative (WAI) who developed the Web Content Accessibility Guidelines 1.0 that was approved in May 1999 and is currently the stable and referenceable version.
- Users that visit websites. In the illustration I mention Government websites as the institution with the biggest need, that is because the Accessibility Guidelines are mandatory for governmental implementations.
Before I continue to explain how the WCAG relate to the Section 508 Standards it is important to get a grasp of what the respective guidelines propose and which checkpoints are included.
Checkpoints: Section 508 Standards
The purpose of Section 508 Standards is explained by Authority 29 U.S.C. 794d: “The purpose of this part is to implement section 508 of the Rehabilitation Act of 1973, as amended (29 U.S.C. 794d). Section 508 requires that when Federal agencies develop, procure, maintain, or use electronic and information technology, Federal employees with disabilities have access to and use of information and data that is comparable to the access and use by Federal employees who are not individuals with disabilities, unless an undue burden would be imposed on the agency. Section 508 also requires that individuals with disabilities, who are members of the public seeking information or services from a Federal agency, have access to and use of information and data that is comparable to that provided to the public who are not individuals with disabilities, unless an undue burden would be imposed on the agency.”
|Non-text elements||A text equivalent for every non-text element shall be provided (e.g., via "alt", "longdesc", or in element content).||(a)|
|Multimedia presentation||Equivalent alternatives for any multimedia presentation shall be synchronized with the presentation.||(b)|
|Color||Web pages shall be designed so that all information conveyed with color is also available without color, for example from context or markup.||(c)|
|Style Sheets||Documents shall be organized so they are readable without requiring an associated style sheet.||(d)|
|Server-side image maps||Redundant text links shall be provided for each active region of a server-side image map.||(e)|
|Client-side image maps||Client-side image maps shall be provided instead of server-side image maps except where the regions cannot be defined with an available geometric shape.||(f)|
|Data tables||Row and column headers shall be identified for data tables.||(g)|
|Markup & tables||Markup shall be used to associate data cells and header cells for data tables that have two or more logical levels of row or column headers.||(h)|
|Frames||Frames shall be titled with text that facilitates frame identification and navigation.||(i)|
|Flickering||Pages shall be designed to avoid causing the screen to flicker with a frequency greater than 2 Hz and lower than 55 Hz.||(j)|
|Text-only page||A text-only page, with equivalent information or functionality, shall be provided to make a web site comply with the provisions of this part, when compliance cannot be accomplished in any other way. The content of the text-only page shall be updated whenever the primary page changes.||(k)|
|Scripting languages||When pages utilize scripting languages to display content, or to create interface elements, the information provided by the script shall be identified with functional text that can be read by assistive technology.||(l)|
|Applets, plug-ins or other applications||When a web page requires that an applet, plug-in or other application be present on the client system to interpret page content, the page must provide a link to a plug-in or applet that complies with §1194.21(a) through (l).||(m)|
|Electronic forms||When electronic forms are designed to be completed on-line, the form shall allow people using assistive technology to access the information, field elements, and functionality required for completion and submission of the form, including all directions and cues.||(n)|
|Navigation links||A method shall be provided that permits users to skip repetitive navigation links.||(o)|
|Timed response||When a timed response is required, the user shall be alerted and given sufficient time to indicate more time is required.||(p)|
Checkpoints: Web Content Accessibility Guidelines
The guidelines as described by the W3C explain how to make Web content accessible to people with disabilities. “The guidelines are intended for all Web content developers (page authors and site designers) and for developers of authoring tools. The primary goal of these guidelines is to promote accessibility. However, following them will also make Web content more available to all users, whatever user agent they are using (e.g., desktop browser, voice browser, mobile phone, automobile-based personal computer, etc.) or constraints they may be operating under (e.g., noisy surroundings, under- or over-illuminated rooms, in a hands-free environment, etc.). Following these guidelines will also help people find information on the Web more quickly. These guidelines do not discourage content developers from using images, video, etc., but rather explain how to make multimedia content more accessible to a wide audience.”
|01.||Provide equivalent alternatives to auditory and visual content.|
|02.||Don't rely on color alone.|
|03.||Use markup and style sheets and do so properly.|
|04.||Clarify natural language usage.|
|05.||Create tables that transform gracefully.|
|06.||Ensure that pages featuring new technologies transform gracefully.|
|07.||Ensure user control of time-sensitive content changes.|
|08.||Ensure direct accessibility of embedded user interfaces.|
|09.||Design for device-independence.|
|10.||Use interim solutions.|
|11.||Use W3C technologies and guidelines.|
|12.||Provide context and orientation information.|
|13.||Provide clear navigation mechanisms.|
|14.||Ensure that documents are clear and simple.|
Considerations when implementing for Section 508 Compliancy
Section 508 has three Levels of priority: Level 1, Level 2 and Level 3. WCAG has also three levels of priority, but they are slightly different and named A, AA, AAA. This is an important distinction especially when testing with automated tools like Bobby because - and be aware of this - Level A compliancy NOT EQUALS Level 1 compliancy. Here is why:
When the ITAW handed Paragraph 1194.22 to the WAI (step 1) and after the WCAG 1.0 were completed and handed back to the ITAW (step 2) the Access Board released a Note to §1194.22:
- The Board interprets paragraphs (a) through (k) of this section as consistent with the following priority 1 Checkpoints of the Web Content Accessibility Guidelines 1.0 (WCAG 1.0) (May 5, 1999) published by the Web Accessibility Initiative of the World Wide Web Consortium:
Section 1194.22 Paragraph WCAG 1.0 Checkpoint (a) 1.1 (b) 1.4 (c) 2.1 (d) 6.1 (e) 1.2 (f) 9.1 (g) 5.1 (h) 5.2 (i) 12.1 (j) 7.1 (k) 11.4
- Paragraphs (l), (m), (n), (o), and (p) of this section are different from WCAG 1.0. Web pages that conform to WCAG 1.0, level A (i.e., all priority 1 checkpoints) must also meet paragraphs (l), (m), (n), (o), and (p) of this section to comply with this section.
Item 2 is especially important because it means that a discrepancy between WCAG and Section 508 exists that requires a Section 508 Level 1 conformant site has to meet more than just Level A of the WCAG.
Step 3 and step 4 complete the process to create accessible.htm - it is basically up to you to apply the guidelines and produce accessible code.
Best Practices for Accessiblity
Follow my Best Practices blog entries to get more in-depth knowledge on what exactly you need to do to meet all the Section 508 compliancy checkpoints as outlined by the WCAG. Blog entries available so far:
- Section 508 Standards; Authority: 29 U.S.C. 794d; http://www.section508.gov/index.cfm?FuseAction=Content&ID=12
- Chisholm, W., Vanderheiden, G., Jacobs, I. (editors); Web Content Accessibility Guidelines 1.0; http://www.w3.org/TR/WCAG10/