Figure 12.23. Range of accessible portable computers (photograph of the PAC Mate™ computer range by kind courtesy of Freedom Scientific, USA)

display unit. The use of the Braille display can be seen in the remaining four units of Figure 12.23. These machines support a wide range of software and use the JAWS® screen reader software.

12.7 Accessible Internet

Being able to access and use the Internet is becoming increasingly important for full participation in society. There are moves toward the information society, with all facilities and services available on-line. The term ‘digital divide’ is often used to describe the increasing gap between those who do and do not have access to information and communications technology. As currently envisaged, the information society has a number of disadvantages and may lead to increasing inequalities. However, discussion of the social role and impacts of information technology is outside the scope of this book. What is relevant here is that disabled people are able to have the same quality and extent of access to and use of information technology as non-disabled people. Currently this is not the case.

In particular, many websites have been designed in ways that are difficult to navigate or are inaccessible to tools like screen readers. Sites that offer services like shopping or banking need to be carefully designed for access by visually impaired and blind people. Since these sites are popular and often provide an essential service to those who experience serious barriers to leaving the house, inaccessibility can be very frustrating and discriminatory for potential visually impaired and blind customers. There are also disadvantages for the firms and other organisations that do not make their websites accessible including loss of custom and the perception of poor public relations and service levels. Thus, firms and organisations could benefit from making their websites accessible.

424 12 Accessible Information: An Overview

12.7.1 World Wide Web Guidelines

There are a number of different initiatives to make the Web more accessible. One of the best known is the World Wide Web Consortium (W3C Web Accessibiliy Initiative), which was established in October 1994 to help make the Web more accessible to everyone. The W3C is currently trying to do this by developing common protocols that promote the evolution and ensure the interoperability of the Web.

The W3C is involved in four domains: architecture, user interface, technology and society, and the Web Accessibility Initiative (WAI). The W3C set up the Web Accessibility Initiative (WAI) to ensure that the Web is accessible to everyone, including disabled people and people using older computers and older version web browsers. It is working in five key areas: technology, guidelines, tools, education and outreach, and research and development.

The Web Content Accessibility Guidelines aim to enable the creation of webpages that are accessible to everyone, including disabled people, people using older computers and older version browsers and people working in noisy or otherwise unfavourable environments. In some countries, webpage accessibility is required by legislation on accessibility to disabled people. In addition, webpages are generally intended to have as wide a distribution as possible, so there are clearly benefits in including disabled people and people with older computers and browsers and disadvantages in excluding them.

People who have a sensory impairment often use assistive technologies when using the Internet. These technologies are very helpful, but require appropriate webpage design to allow access. When the assistive technology finds something on the page it cannot deal with, the page becomes inaccessible to the user. Examples of such problems include unlabelled graphics, badly positioned frames and tables within a page.

The guidelines are intended to be simple and straightforward to use and the grouping into four categories in the second version may make them easier to remember. They suggest simple common sense standards such as providing a textual description of a graphic or a sound through the “alt-text” or “long-desc” tags. This should also benefit people who have a slow Internet connection or who prefer not to download graphics, as well as blind people. If people are working in a noisy environment they may not be able to hear sound clips so providing a text alternative would be of benefit to them, as well as to deaf people and people who prefer text or find it easier to understand than graphics.

The use of guidelines, such as those drawn up by the W3C, has a number of advantages. In particular it provides a structured and easily followed approach to designing webpages to make them accessible. This makes it much easier to identify potential and actual problems and develop technologies to resolve them.

However, some web designers may feel restricted by the guidelines in what they can put on the webpage and therefore discouraged from using them. For example, designers may feel that they cannot use graphics on webpages in case a visually impaired person tries to access their page. This is not the case. The aim

is not to restrict the creativity of web designers, but to ensure that they extend this creativity to designing webpages which can be accessed by everyone (while remaining interesting and attractive). Thus, the designer simply needs to consider what graphics are to be put on the page and provide a description to accompany the graphics. Particular care needs to be exercised when using tables and frames. It should be noted that older screen readers may have problems reading them.

12.7.1.1 W3C Accessibility Guidelines 1.0

WCAG 1.0 was the first version of the guidelines, which was published in 1999. It comprises 14 guidelines based on the following two themes:

1.Ensuring graceful transformation This means that the pages remain accessible for people with physical, sensory and cognitive impairments and despite any limitations of the environment they are working in, such as noise, and technological barriers, such as using old computers and old version browsers. Guidelines 1–11 address this theme. Key principles include the following:

•Separating structure from presentation.

•Providing text, including text equivalents, as text can be made available to almost all browsing devices and accessible to almost all users.

•Creating documents that can be used by blind and/or deaf users by providing information to other sensory modalities. This does not mean a prerecorded audio version of a whole site, as blind users (who are not also deaf) can use screen readers to access text information.

•Creating documents that do not rely on a particular type of hardware, so they can be used by people who do not use a mouse, with small, low resolution, black and white screens, who use voice or text output.

2.Making content understandable and navigable Language should be clear and simple and the mechanisms for navigating between and within pages should be comprehensible. Navigation tools and orientation mechanisms should be provided in pages to maximise usability and accessibility. This is particularly relevant to users accessing pages one word at a time through speech synthesis or Braille display or one section at a time through a small or magnified display. Guidelines 12–14 address this theme.

Each of the guidelines has a number of associated checkpoints. The checkpoints have been assigned three priority levels by the Working Group based on their impact on accessibility:

Priority 1. Content must satisfy this checkpoint or one or more groups will find it impossible to access the information. Satisfying this checkpoint is a basic requirement for some groups to use web documents.

Priority 2. Content should satisfy this checkpoint or one or more groups will find it difficult to access information in the document. Satisfying this checkpoint will remove significant barriers to accessing web documents.

426 12 Accessible Information: An Overview

Priority 3. Content may address this checkpoint or one or more groups may find it somewhat difficult to access information in the document. Satisfying this checkpoint will improve access to web documents.

A number of suggested techniques for achieving it are stated for each checkpoint. There are three levels of conformance: A, Double-A and Triple-A which comprise satisfaction of all Priority 1, all Priority 1 and 2, and all Priority 1, 2 and 3 checkpoints respectively. Conformance claims should specify the guidelines title, its URI, the conformance level, e.g. A and the page site or defined portions of a site covered by the claim. Alternatively one of the three W3C icons can be used on each conforming page with a link to the appropriate W3C explanation.

The fourteen guidelines are as follows:

Guideline 1. Provide equivalent alternatives to auditory and visual content. Guideline 2. Do not rely on colour alone.

Guideline 3. Use mark-up 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 design independence.

Guideline 10. Use interim solutions.

Guideline 11. Use W3C technologies and guidelines. Guideline 12. Provide context and orientation information. Guideline 13. Provide clear navigation mechanisms. Guideline 14. Ensure that documents are clear and simple.

For illustration, the checkpoints and techniques for the first two guidelines will be stated. Guideline 1 has the following five checkpoints, with checkpoints 1.1–1.4 Priority 1 and 1.5 Priority 3:

Checkpoint 1.1. Provide a text equivalent for every non-text element, for instance using ‘alt’ and ‘longdesc’ in element content. Non-text elements includes images, graphics, symbols, image map regions, animations, applets, program objects, frames, scripts, audio files and video.

Checkpoint 1.2. Provide redundant text links for each active region of a serviceside image map.

Checkpoint 1.3. Provide an auditory description of the important information of the visual track of a multimedia presentation until user agents can automatically read out its text equivalent.

Checkpoint 1.4. Synchronise equivalent alternatives, such as captions or auditory descriptions of the visual track with the presentation for any time-based multimedia presentation, such as a video or animation.

Checkpoint 1.5. Provide redundant text links for each active region of a client-side image map until user agents are able to provide text equivalents for client-side image map links.

Core techniques for achieving Checkpoint 1.1 include the use of text equivalents, whereas HTML techniques include the following:

•Images used as bullets and graphical buttons.

•Text for images used as links.

•Short text equivalents, such as ‘alt-text’, and long descriptions of images.

•Text (and non-text) equivalents for applets, programmatic objects, multimedia and client-side image maps.

•Describing frame relationships and writing for browsers that do not support FRAMEs.

•Alternative presentation of scripts.

12.7.1.2 W3C Accessibility Guidelines 2.0

A revised form of the Web Content Accessibility Guidelines is currently being developed in consultation with users and drawing on the experience with WCAG1. The Web Content Accessibility Guidelines 2.0 (WCAG 2) are still in draft form and may be updated or replaced by subsequent documents. The final agreed version will be published as a W3C Recommendation, but until then WCAG 1.0 is the stable reference version. Both WCAG 1.0 and 2.0 have the same overall goal of promoting accessibility of web content, and WCAG 2.0 has the following additional aims:

1.Ensuring that the requirements can be applied across technologies.

2.Ensuring that the conformance requirements are clear.

3.Ensuring that the deliverables are easy to use.

4.Addressing a more diverse audience.

5.Clearly identifying who benefits from accessible content.

6.Ensuring that WCAG 2.0 is compatible with WCAG 1.0.

WCAG 2.0 is intended to be more efficiently organised than WCAG 1.0 and to incorporate the experience and errata from WCAG 1.0. In addition, it may adjust the priority of some checkpoints and modify, remove or add requirements to take account of changes in web technologies since the publication of WCAG 1.0. The majority of WCAG 1.0 checkpoints can be mapped into WCAG 2.0 success criteria (http://www.w3.org/WAI/GL/2005/11/23-mapping.html). However, WCAG 2.0 does incorporate a number of additional guidelines, such as the provision of sign language interpretation for multimedia.

The WCAG 2 guidelines are organised into the following four accessibility principles:

Principle 1. Content must be perceivable.

428 12 Accessible Information: An Overview

Principle 2. User interface components in the content must be operable by each user.

Principle 3. Content and control must be understandable to each user.

Principle 4. Content must be robust enough to work with current and future technologies.

Each of these principles has a list of guidelines that address the principle and each principle has a number of success criteria. The success criteria are grouped into three levels of conformance, representing increasing levels of accessibility for the associated guidelines. They are statements that will be true or false according to whether or not the specific web content meets the criteria. The principles, guidelines and success criteria are intended to be applicable to all web-based content and to be independent of the technology used. There are three levels of conformance with the success criteria. Level 1 and level 2 success criteria respectively give a minimum and an enhanced level of accessibility through markup, scripting or other technologies that interact with or enable access, including assistive technologies. Both levels 1 and 2 are intended to be applied to all web resources. Level 3 success criteria enhance accessibility for disabled people and are not applicable to all web resources.

Some guidelines do not have level 1 or level 2 success criteria. The approach to conformance has changed from the previous version WCAG 1.0, in which checkpoints were assigned Priorities 1–3 according to their impact on accessibility, with Priority 3 checkpoints less important than Priority 1 ones. In WCAG 2.0 this is no longer the case and all the criteria are essential for some groups of users.

All the success criteria are intended to be testable by either computer programs or people who understand WCAG 2.0. Tests of this type can be used to determine whether or not the content conforms to the criteria. However, there is some anecdotal evidence that meeting the WCAG 1.0 guidelines has not always been sufficient to resolve all end-user problems and the same may be the case with WCAG 2.0. Therefore, there are advantages in testing being carried out by disabled end-users, though this may not always be feasible.

The guidelines and criteria do not require or prohibit the use of any specific technology, as long as it is supported by accessible user agents, which are defined as software which retrieves and makes available web content for users. This includes web browsers, media players, plug-ins and assistive technology, including screen readers, screen magnifiers and alternative keyboards. However, a particular baseline or set of technologies supported by and active in accessible user agents may be specified for a given web content. In this case the criteria only need to be checked for technologies in the baseline. Web developers can use non-baseline technologies under the following conditions:

•All content and functionality can be accessed using only technologies in the specified baseline.

•The non-baseline technologies do not impede access to the content when used with user agents that either support only baseline technologies or support both baseline and non-baseline technologies.