Week 9: Accessibility and adaptability

What is accessibility?

One of the underlying themes of this course has been the separation of content from presentation. Without this separation (sooner or later) most digital content becomes inaccessible.

The notion of accessibility grew from efforts to provide access to the web for the disabled. However, if the context in which we access digital material changes, we all become disabled. This makes accessibility a challenge for us all. Consequently, attention is now shifting towards the wider notion of adaptability. Adaptable content is capable of transformed into the right content, in the right place, at the right time. For example, there may be times and places when we may

• not be able to see, hear, move, or may not be able to process some types of information easily or at all;
• have difficulty reading or comprehending text;
• not have or be able to use a keyboard or mouse;
• have a text-only screen, a small screen, or a slow Internet connection;
• not speak or understand fluently the language in which the document is written;
• be in a situation where our eyes, ears, or hands are busy or interfered with (e.g., driving to work, working in a loud environment, etc.);
• have an early version of a browser, a different browser entirely, a voice browser, or a different operating system.

There is no magic wand to make your content universally adaptable but there are principles and guidelines that can be applied at the point of creation that can make a significant difference.

W3C Guidelines

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.

It was established by Tim Berners-Lee who has served as the W3C Director since it was founded, in 1994. Tim Berners-Lee is regarded as one of the founders of the World Wide Web. In 1989 he write the first browser/editor/server application while working at the European Organization for Nuclear Research (CERN).

Tim Berners-Lee

We will come back to Tim Berners-Lee when we look at the Semantic Web.

Accessibility guidelines

A core reference document for the principles and ideas associated with accessibility is the W3C Web Content Accessibility Guidelines.
For example, the first guideline explains how we can make images accessible. Some of us may not be able to see images, others may use text-based browsers that do not support images, while others may have turned off support for images (e.g., due to a slow Internet connection). The guidelines do not suggest avoiding images as a way to improve accessibility. Instead, they explain that providing a text equivalent of the image will help to make it accessible.

But how does a text equivalent make an image accessible? The words in the phrase ‘text equivalent’ are important:

• Text content can be presented to the user as synthesized speech, braille, and visually-displayed text. Each of these three mechanisms uses a different sense — ears for synthesized speech, tactile for braille, and eyes for visually-displayed text — making the information accessible to groups representing a variety of sensory and other situations.
• In order to be useful, the text must convey the same function or purpose as the image. For example, consider a text equivalent for a photographic image of the Earth as seen from outer space. If the purpose of the image is mostly that of decoration, then the text ‘Photograph of the Earth as seen from outer space’ might fulfill the necessary function. If the purpose of the photograph is to illustrate specific information about world geography, then the text equivalent should convey that information. If the photograph has been designed to tell the user to select the image (e.g., by clicking on it) for information about the earth, equivalent text would be ‘Information about the Earth’. Thus, if the text conveys the same function or purpose for the user with a disability as the image does for other users, then it can be considered a text equivalent.

The aim is to have content that will transform gracefully in the sense that gracefully means tht the content remains accessible despite any of the constraints described above. The 14 guidelines will provide you with a useful checklist that you can use when building or accessing an information space.

When it might be useful to invoke a Standard, the levels of conformance with these guidlines are identified by the W3C as:

• Conformance Level A: all Priority 1 checkpoints are satisfied;
• Conformance Level Double-A: all Priority 1 and 2 checkpoints are satisfied;
• Conformance Level Triple-A: all Priority 1, 2, and 3 checkpoints are satisfied;

Assignment 9

Using the W3C accessibility Conformance Guidelines, assess the Conformance level of one of the following sites:

http://www.kangaroocenter.com/

http://www.rmit.edu.au/creativemedia

You might find this sample report a useful guide to the way a commercial a report can be produced.
Accessibility report PDF 4.2 MB]

Vision Australia’s Free Accessibility Toolbar

Web Accessibility Toolbar is provided free by the Accessible Information Solutions (AIS) of Vision Australia. It is a tool for advanced users or web developers, that helps you examine the structure, components and accessibility features of any given web page. It installs as an Internet Explorer toolbar and offers several integrated tools to inspect style sheets, tables, frames, images and more, as well as a wide variety of tests and features that are provide by other web sites, including link checks, HTML validation, page download speed, color simulations, page resolutions and much more.

• identifies components of a web page
• facilitates the use of 3rd party online applications
• simulates user experiences
• provides links to references and additional resources

References

• Techniques for Web Content Accessibility Guidelines 1.0, W. Chisholm, G. Vanderheiden, I. Jacobs, eds. This document explains how to implement the checkpoints defined in ‘Web Content Accessibility Guidelines 1.0′. The latest draft of the techniques is available at: http://www.w3.org/TR/WAI-WEBCONTENT-TECHS/
• Synchronized Multimedia Integration Language (SMIL) 1.0 Specification, P. Hoschka, ed., 15 June 1998. This SMIL 1.0 Recommendation is http://www.w3.org/TR/1998/REC-smil-19980615/. The latest version of SMIL 1.0 is available at http://www.w3.org/TR/REC-smil.