Multimedia on the Web: Making it Accessible – W3C, WAI, and You

Multimedia on the Web: Making it Accessible – W3C, WAI, and You

Editor: A couple of years ago when we first started hearing about multimedia on the web, there was a lot of concern about the multimedia being accessible. We seem to hear less and less about that. Does that mean that the battle has been won, or abandoned? Here’s the current status, as presented at the TDI Convention by Judy Brewer, the Director of the Web Accessibility Initiative (WAI) at the WWW Consortium (W3C).


W3C and WAI

W3C is an international, vendor-neutral consortium that comprises about 400 organizations. Its purpose is to develop technical standards for the web, including those for interoperability and universality.

W3C facilities are hosted in three locations – the United States (at MIT), Europe, and Japan.

The organization consists of four domains – architecture, interaction, technology and society, and WAI. It’s unusual for accessibility to be a major division of an international standards committee; but it’s also wonderful because it allows accessibility to be designed in rather than added on.

W3C stakeholders include industry, the disability community, research organizations, and governments; the organization is sponsored by government and industry organizations.

The five areas of WAI activity are technology support, guidelines, tools, education/outreach, and research coordination; each supports the overall goal of ensuring that web multimedia remains accessible.

Technology Support – Every technology specification produced by the W3C can support accessibility. For example, the SMIL (Synchronized Multimedia Integration Language) specification, which deals with multimedia presentations on the web, specifies that presentations accommodate captions and descriptions (for the blind). The WAI reviews 30 to 40 specifications a year.

Tools – The tools committee works to improve the tools available to evaluate accessibility of websites.

Guidelines – This committee oversees the development of the WAI guidelines, which define methods and standards that encourage accessibility.

Education and Outreach – These folks work to make people aware of web accessibility issues and the tools available to develop accessible applications.

Research Coordination – The Research Coordination group looks at advanced web technologies and works to ensure that they support accessibility. For example, what are the issues with three-dimensional web representations (3D), remote collaboration, or streaming CART?

Cross Disability Requirements

In the early years of web development, the blindness community was very active in ensuring that web technology was accessible to blind people. Unfortunately, the other disability communities were not so involved and were often overlooked. And no one ever thought about dealing with multiple disabilities.

People with visual disabilities are concerned with described graphics and video, well marked-up tables or frames, keyboard support, and screen reader compatibility.

People with hearing loss are primarily interested in captioning, and those with poor English skills may be interested in supplemental illustration.

People with physical or speech impairments focus on keyboard or single switch support, which are alternatives for speech input on voice portals for those who can’t talk. (It seems that many state governments are building voice portals.)

Those with cognitive and neurological disorders encourage the development of consistent navigation, appropriate language level, thorough illustrations, and the absence of flickering or strobing effects (for those with strobing epilepsy problems).

General accessibility guidelines include:
1. Support the availability of information in multiple modalities.
2. Ensure that appropriate language level is provided.
3. Maintain a clear and consistent navigation pattern.
4. Allow the user to choose her display options.

As you might imagine, it’s not always easy to convince people to develop accessible websites. It does cost more money to do it that way, and you may have to show a return on that additional expenditure to justify the added cost. Here are some additional advantages of accessible software: Increased usability, increased device independence, increased audience, support for low literacy levels, improved content searchability, increased support for the Semantic Web (advanced machine to machine capability built into the future web), increased support for internationalization, increased support for low bandwidth, and reduced site maintenance.

Current W3C guidelines include:
Web Content Accessibility Guidelines 1.0
Authoring Tool Accessibility Guidelines 1.0
User Agent Accessibility Guidelines 1.0 (browsers and multimedia layers, interoperability with assistive technologies)
XML Accessibility Guidelines (draft)

The first three have been released as W3C Recommendations. The fourth is in draft and may get combined with other guidelines.

Web Content Accessibility Guidelines

The Web Content Accessibility Guidelines (WCAG) were completed in May 1999 and consist of several layers, including guidelines, “normative” checkpoints (what you need to do), and techniques (how to do it).

The W3C is currently developing a working draft of Revision 2.0 of the WCAG. The most recent draft is dated June 24, 2003. The goals of this revision are to make the standard easier to understand and implement and to address more advanced web technologies.

The working draft contains the following requirements of interest to people with hearing loss:
1. text captions for all audio content – size, color, placement, etc. must be under user control.
2. screen enlargement and screen reader access must be included (applicable to the deaf/blind).
3. Supplemental illustration should be provided where appropriate – This is tough to do on a website – one issue is that there are no universally accepted symbols people can use in different languages.
4. Streaming sign (ASL) – This is another tough issue, because there is no agreement on the best format for presenting sign. Is film better than digital representations? Countries that speak English have different sign languages; some languages don’t have digital representations.

Authoring Tool Accessibility Guidelines

Probably the most important requirement to make the web accessible is to ensure that authoring tools make it easy to incorporate accessibility. The guidelines presented in the Authoring Tool Accessibility Guidelines (ATAG) do just that. This document was released in Feb 2000. It’s unfortunate that Section 508 does not require conformance to these guidelines; if it did, we’d be two or three years ahead of where we are right now.

User Agent Accessibility Guidelines

The User Agent Accessibility Guidelines deal with the programs a person uses to interface with the web, including web browsers and media players. Requirements on this software includes:
1. Support input and output device independence.
2. Insure user access to all content.
3. Allow certain configurations not to render some content that may reduce accessibility.
4. Insure user control of rendering.
5. Insure user control of user interface behavior.

Multimedia on the Web

The SMIL Synchronized Multimedia Integration Language (SMIL 1.0 and 2.0) specifications define how to ensure that information presented in multiple media (e.g. video and sound) is synchronized in time. This includes ensuring that captions are synched with audio files and descriptions are synched with video files. For example, if you choose to view a video in slow motion, both the sound and the corresponding captions must be slowed down.

One of the issues here is the convergence of different technologies to serve similar functions on the web. For example, movie subtitles, captions, and karaoke lyrics exist as three separate technologies in the “real world”. But it would sure be nice if all three could be implemented the same way on the web using some common “timed text” specification.

The benefits of this and other “standards harmonization” include:
1. Larger market for authoring tools and evaluation tools
2. Increased reusability of training resources for web designers
3. Increased ability to monitor accessibility

Developing Organizational Policies

A proposed methodology for developing an organizational policy includes the following steps:
1. Clearly reference the governing guidelines.
2. Specify a conformance level.
3. Define the scope of the covered site.
4. Set implementation milestones.

The United States, Canada, Australia, the European Union, and New Zealand governments currently require their websites to be accessible. Many US states have similar requirements. It is crucial that accessibility capabilities be incorporated into all web development tools. If you’re in a position to buy authoring tools, please be sure to ask all the vendors if their offerings conform to W3C standards – and don’t buy them unless they do!

WAI website:
SMIL website: