W3C

Relationship between Mobile Web Best Practices (MWBP) and Web Content Accessibility Guidelines (WCAG)

Overview

W3C Working Draft 26 May 2009

This version:
http://www.w3.org/TR/2009/WD-mwbp-wcag-20090526/
Latest version:
http://www.w3.org/TR/mwbp-wcag/
Previous version:
http://www.w3.org/TR/2008/WD-mwbp-wcag-20080703/
Editors:
Alan Chuter, Fundación ONCE / Technosite.
Yeliz Yesilada, University of Manchester (WCAG 1.0 pages).

This document (will be in final version) also available as a [single HTML file].


Abstract

This technical report describes the similarities and differences between the requirements in Web Content Accessibility Guidelines (WCAG) and Mobile Web Best Practices 1.0 (MWBP). Introductory information and links to related documents are in Web Content Accessibility and Mobile Web: Making a Web Site Accessible Both for People with Disabilities and for Mobile Devices.

Status of This Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

This document was developed jointly by the Mobile Web Best Practices Working Group of the Mobile Web Initiative (MWI) and the Education & Outreach Working Group (EOWG) of the Web Accessibility Initiative (WAI).

The Working Groups believe this document is complete and do not anticipate any substantive changes. This draft is provided as a last chance for review and feedback before publication as a Working Group Note.

Please send comments on this document to public-bpwg-comments@w3.org (with public archive) by 16 June 2009. Reviewers are invited to consider the following aspects of the document:

Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document was produced by groups operating under the 5 February 2004 W3C Patent Policy. The groups do not expect this document to become a W3C Recommendation. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the Mobile Web Best Practices Group and also maintains a public list of any patent disclosures made in connection with the deliverables of the Education and Outreach Working Group; those pages also include instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

Changes since the last version of this document are described in the changelog of updates and modifications, available separately. Comments on this new version are welcome.

Audience

Readers of this document are expected to be familiar with the creation of Web sites, and to have a general familiarity with the technologies involved, such as Web servers and HTTP but not necessarily in mobile-specific technologies. It is important to understand the other W3C Recommendations to which it refers (see Appendix A: References).

The document is not targeted solely at developers; others, such as interaction and graphic designers are encouraged to read it. Many readers of the document are likely to have a good knowledge of general Web accessibility but are concerned with the problems of persons with disabilities in the mobile context.


Table of Contents


Introduction

This technical report helps Web developers meet both Web Content Accessibility Guidelines (WCAG) and Mobile Web Best Practices 1.0 (MWBP). It describes the similarities and differences between requirements in WCAG and MWPB. It is designed primarily to help Web developers who have worked with either WCAG or MWBP to learn about the additional requirements in the other.

This technical report is a companion document to WCAG and MWBP, and does not replace either of those. The actual Web Content Accessibility Guidelines document should be used to make Web content accessible to people with disabilities, and the Mobile Web Best Practices document should be used for best practices for making Web content for mobile devices.

Many MWBPs have the added benefit of partial or complete compliance with certain WCAG success criteria or checkpoints. However, WCAG is often more detailed or describes a different aspect of the same concept. It should not be assumed that following any BP will ensure accessibility or that a success criterion or checkpoint will ensure compliance with MWBPs. To ensure compliance it is important to always consult the Mobile Web Best Practices or the Web Content Accessibility Guidelines directly.

W3C WAI recommends using WCAG 2.0, instead of WCAG 1.0. If your site is required to meet WCAG 1.0, you can develop it to meet both WCAG 1.0 and WCAG 2.0.

Differences of Approach Between WCAG and MWBP

WCAG and MWBP both aim to improve the Web interaction of users who experience barriers due to either disabilities or the device used to access the Web. However, WCAG and MWBP have slightly different approaches. For example, a key feature of WCAG 2.0 success criteria is that they are specifically designed to be testable statements. Although some of the Mobile Web Best Practices are testable, they are not all intended to be testable.

While the two documents show significant overlap in many areas, there are different degrees of overlap between individual technical requirements, so that there is not always a one-to-one mapping between them. For instance, WCAG has some requirements that are specific to accessibility needs of people with disabilities, and that are not relevant for mobile devices (for example, requirements that specifically address assistive technology). Conversely, MWBP has other requirements that are specific to mobile devices only (for example, requirements to minimize battery consumption and CPU power). However, in general many requirements are applicable for both groups of users (for example, requirements for color contrast, flexible font sizes, etc.).

The relationship between WCAG and MWBP is too complex for a simple mapping table to adequately communicate what developers need to do to meet both. For example, in some cases complying with a specific WCAG provision will meet the related MWBP; however, the inverse is not always true and complying with the MWBP provision will not necessarily meet the related WCAG provision. Thus, there is no simple mapping table between WCAG and MWBP. The document Shared Web Experiences: Barriers Common to Mobile Device Users and People with Disabilities shows generally how WCAG and MWBP relate.

Priorities and Levels

WCAG 1.0 checkpoints are Priority 1, 2, or 3. WCAG 2.0 success criteria are Level A, AA, or AAA.The Mobile Web Best Practices (BP) are not assigned priorities or levels.

How to Use This Document

Please see the following introductory and related information:

This document includes four subpages that each address a different scenario. Most people will use only one of the subpages described below:

Web Content Accessibility Guidelines 2.0 and
Mobile Web Best Practices 1.0 Together

If you are not familiar with either WCAG or MWBP:

  1. Use Shared Web Experiences: Barriers Common to Mobile Device Users and People with Disabilities (which is also available in a table format) for an overview of the barriers and solutions shared by WCAG 2.0 and MWBP.
  2. Become familiar with WCAG 2.0.
  3. Use the WCAG 2.0 to MWBP subpage of this document to learn about the additional requirements in MWBP.
  4. Become familiar with MWBP.

For the latest version of any W3C specification, please consult the list of W3C Technical Reports.

[WAI/Experiences]
Shared Web Experiences: Barriers Common to Mobile Device Users and People with Disabilities, eds. Yesilada, Y., Chuter, A., and Lawton Henry, S.
[WAI/Mobile]
Web Content Accessibility and Mobile Web: Making a Web Site Accessible Both for People with Disabilities and for Mobile Devices, eds. Thorp, J. and Lawton Henry, S.
[MWBP1.0]
Mobile Web Best Practices 1.0, eds. Rabin, J. and McCathieNevile, C., November 2006 (see http://www.w3.org/TR/mobile-bp/)
[WCAG1.0]
Web Content Accessibility Guidelines 1.0, eds. W. Chisholm, G. Vanderheiden and I. Jacobs, May 1999 (see http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505/)
[WCAG2.0]
Web Content Accessibility Guidelines 2.0, eds. B. Caldwell, M. Cooper, L. Guarino Reid and G. Vanderheiden (see http://www.w3.org/TR/WCAG20/)

Appendix B: Acknowledgements

This document was developed by the WAI Education & Outreach Working Group and the Mobile Web Best Practices Working Group. Charles McCathieNevile (Opera Software) also contributed to this document.