Note: This document is a draft and should not be referenced or
quoted under any circumstances.
- Introduction
- Increase Market Share and Audience Reach
- Improve Efficiency
- Demonstrate Social Responsibility
- Reduce Legal Liability
- Benefits Matrices
1. Introduction
This document is one of several resources created to assist the
preparation of a business case for the implementation of Web accessibility.
It describes the many business, technical and other benefits to the
organization above and beyond the straightforward benefits to people with
disabilities that can be realized by applying the Web Content Accessibility
Guidelines (WCAG 1.0) to Web sites.
Conformance with the WCAG 1.0 (and other
W3C) guidelines will enhance the market share and audience
reach of your Web site by increasing its general usability. Adoption of
WCAG 1.0 recommendations also demonstrates your commitment
to social responsibility and equity of access to information and services. In
addition, many of the WCAG 1.0 checkpoints will directly
improve the performance of your Web services and reduce the maintenance
effort required.
It should be noted that the following list contains some duplication; a
number of the WCAG 1.0 checkpoints clearly benefit more
than one general area as highlighted by the benefits matrices at the end of
this document.
2. Increase Market Share and Audience Reach
Increasing discovery, access and usability of your Web site for all
visitors is a major benefit from applying many of the WCAG
1.0 checkpoints. Furthermore, the proportion of people with disabilities can
range up to 20 percent in some populations. A significant portion of those
people with disabilities - in some countries as many as 8% to 10% of the
overall population - can benefit from Web sites' conforming with
WCAG 1.0.
Improve usability for non-disabled and
disabled visitors
The usability of Web sites is becoming a very important topic as
organizations struggle to reach, and especially to retain, a wider audience.
Since implementation of the WCAG 1.0 checkpoints has the
effect of increasing the usability of Web sites, following the guidelines
will help you achieve this.
- Clear and consistent navigation - people
often avoid a Web site after an initial visit because they encounter
difficulties navigating complex collections of information or cannot find
(or refind) the item they wanted. Applying the WCAG
1.0 recommendations for clear and consistent navigation will help reduce
this problem.
- Device independence because of situational
usage - an increasing number of people use a variety of technologies to
access the Web and the WCAG 1.0 techniques can expose
critical content and facilitate interaction in all these situations.
- While the primary Web device for some may be a multimedia-capable
desktop computer with a high-bandwidth connection, those same people,
and others, may also choose to access the Web with personal digital
assistants, mobile phone browsers, or other, less capable Web
devices, possibly over lower-bandwidth connections.
- Some users may find themselves in noisy environments where audio
content may not be easily heard; having a text-based alternative
becomes critical.
- In some situations glare on a screen may make seeing video, or even
text-based content, difficult so having content that can be rendered
with a voice synthesizer can be beneficial.
- An increasing number of users will access the Web with
hands-free/eyes-free devices.
- Clear and understandable content - this will
immediately increase the size and breadth of the audience that can
benefit from your Web site.
- Text alternatives
- "D" links and "longdesc" attribute - since the message you hope to
convey with complex graphics such as photographs, graphs and diagrams
may not be immediately obvious to (or even viewable by) some visitors
a clear text description of what the image means or conveys can be a
great boon to your audience.
- Text descriptions for multimedia files - for any number of reasons
(and many are identified in this document) a significant number of
users worldwide will not be able to access content contained in
multimedia files. Providing alternative text-based content will
significantly increase its availability.
- Captioning - audio content will not be
accessible to all users. Providing alternative textual content will
significantly increase the number of people who will "hear" your
message.
- Color contrast - contrasting colors for page
background and text make for easier reading. Dark text on a light
background is usually the best combination for non-visually impaired, but
utilising style sheets for controlling text and background colors allows
others to chose the best combination for their needs and current
environment (in other words, they may choose one style sheet while at
their desktop computer, and another while using their laptop or
PDA at a meeting or on an airplane). Also be aware
that 8% to 10% of the male population in many countries exhibit some form
of color blindness.
Support for Low Literacy Levels
In every nation there are significant numbers of people who do not share
the same level of literacy as the professionals who design your Web sites and
write your content. Following the WCAG 1.0 recommendations
can support users who have low literacy levels and those people for whom the
language of your Web site is not their first.
- Clear Navigation - adopting a clear,
consistent and logical navigation style across your entire Web site
assists all users to understand your site and accelerates their
familiarity. Provision of navigation bars, site-maps and linked tables of
contents will increase the chances that your visitors will find what they
are looking for.
- Clear Content
- Many studies have shown that most people do not "read" Web pages -
at least not onscreen - instead they "scan". With this in mind, the
use of simpler language rather than marketing or technical jargon
will increase their comprehension, and their satisfaction.
- Non-text elements such as illustrations and graphs should be
relevant to the text, placed nearby the relevant text, and described
or introduced within the text.
- Separate structure from presentation - the
clear and consistent use of structural markup to convey meaning and
structure will assist your visitors in comprehending your site and
locating the information of interest or importance to them.
Improve Search Engine listings and Resource
Discovery
Simply stated, content that is not text-based is not available to search
engines or other automatic data-mining applications. Much important content
on your site may be "locked-up" in unsearchable formats. By exposing this
content you can significantly increase the chance that people searching for
particular content on your site can find it. From a strategic point of view,
anything you can do to increase the likelihood that your site will be found
is a positive benefit.
- Clearer, understandable content - using
commonly used and understood words, phrasing and grammar will increase
the likelihood that people using simple search-criteria will find your
site.
- Text alternatives
- Alternative text - an image without alt-text can only be found by
its file name. In many cases the file name is a cryptic and unhelpful
string of characters. Adding short descriptive phrases via alt-text
means that search-engines can find particular images because their
description has been indexed. The alt-text for images that are about
your site's content can help raise your ranking on the search
engine's listings.
- "D" links and "longdesc" attribute - much important content on your
site may be locked-up in complex images such as photographs, charts
or graphs. Describing these more fully using "D" links and the
"longdesc" attribute makes that content available to search
engines.
- Text descriptions for multimedia files - a text-based description
of the action or content of a Web based video will make the important
information contained in that expensive and informative medium
available to search engines. Otherwise, only the file name is
available for reference.
- Captioning - audio file formats
are searchable only by their file names, which as has been mentioned,
can be cryptic and unhelpful. Providing full-text captioning (either
synchronized with the audio track using SMIL, or
as a separate transcript) allows the content, especially for files
containing dialog or speech, to be indexed and searched.
- Table summaries - clear summaries
describing the purpose of a table will be indexed by a search engine
while the table content may actually be less meaningful when indexed
cell-by-cell. Furthermore, table captions, by providing a heading for the
table, will also be indexed by many search engines.
- Structure Documents with Markup - some
search engine spiders actually use the text within your header tags,
e.g.<H1>, <H2> etc., to rank Web pages and accord increased
relevance to this text.
- Metadata - following metadata standards
for describing documents, and relationships between documents can
significantly increase the usefulness of your Web content, both to the
people searching for your products or services, and for your own business
reporting and filing needs. International standards for metadata are
evolving - IMS
is being used within the education sector and Dublin Core is being widely adopted
with the government sector. Information that cannot be found or
identified easily is costly.
Support for the Semantic Web
The Semantic Web is an extension of the current Web in which information
is given well-defined meaning, better enabling computers and people to work
in cooperation. The Semantic Web will enable data on the Web to be defined
and linked in a way that it can be used by machines not just for display
purposes, but for automation, integration and reuse of data across various
applications. Organizations adopting elements of the Semantic Web will be
positioned to increase their audiences as this new technology is
developed.
- Metadata is the first implementation of
structured information about resources on the Web. Implementations such
as "Dublin Core" and "IMS" when adopted widely and
implemented through RDF will enable
machine retrieval and collation of information.
- Separate Structure from Presentation -
utilising structural markup for your information adds definition to your
pages in a machine recognisable format, i.e.
HTML tags, and will assist the migration from the
"World Wide Web" to the "Semantic Web" where agents will be able to glean
information from your site.
- Clear Content
& Text Alternatives - for business, the Semantic Web expands the
market place through the clarity of the meta data during seamless content
management in all alternative routes "anytime anywhere". Following the
WAI guidelines ensures clear alternative routes by way
of the Semantic Web to textual meanings archived in data bases.
- Device independence - Web sites that adopt
the principles of device independence will be well positioned to add
semantics allowing the filtering and selecting of relevant content for
devices with lower bandwidth or those requiring different navigation
approaches.
Repurpose content for multiple formats or
devices
In the continually evolving world of Web applications and Web technologies
it makes sense to design your content and service so that it can be adapted
quickly and efficiently to meet any new circumstance. Using existing design
techniques like those in the WCAG 1.0 will ensure that
your message will be readily available to your changing (and expanding)
customer base and any new technologies they may choose.
Separate structure and semantics from
presentation. If you markup or provide content that is intimately linked with
one particular display or access technology, your content is likely to be
inaccessible or unusable on other technologies. The ideal situation is one in
which you provide the content (structure and semantics) separately from the
presentation of the information. You can then more easily create alternate
layouts for different Web devices, alternate views that can be chosen by the
client, or let the differing Web devices render the content in the way that
best suits their capabilities.
- Use of styles - master style sheets (a
files on your server containing style markup relating to all pages on a
site) allows quick and comprehensive changes to the overall look and feel
of your site. A style sheet file can contain display instructions for
numerous display technologies. This means that instead of having to
reedit every content page of your site to meet the needs of a new
technology, only the master style sheet files need to be changed. Style
sheets also allow different presentation to be made available for
different devices or end purposes such as screen and printer or report
and lecture presentation.
- Color independence - avoiding the use of
color to highlight importance or differentiate features on your pages
will enable your content to be more easily made available on devices that
cannot display color.
- Use of XHTML &
XML - use of these emerging language specifications
(in conjunction with the appropriate use of style sheets) will make
automatic conversions of content for alternative display even easier.
XHTML and XML are ideally suited to
machine manipulation of information.
- Avoiding deprecated features of
HTML - many of the earlier markup features of
HTML have been dropped in later releases in favour of
controlling these aspects of the presentation though styles or style
sheets. Applying valid HTML will assist you repurpose
content for future formats and devices.
Increase support for
Internationalization
In an expanding global marketplace, ignoring or alienating potential
clients or customers in other countries may be detrimental to your business.
The WCAG 1.0 describes a number of techniques that can
enhance your ability to reach this global audience.
- Captioning of audio/video in
multiple languages - for organizations with multinational clients,
providing low cost captioning of audio and video content in other
languages can be an effective method of reaching that wider audience.
Translation and captioning are, in most cases, less costly than producing
complete alternative language versions of the more expensive media.
- Redundancy of another modality to assist understanding/comprehension -
a multilingual user may be less comfortable when absorbing content that
is not available in their primary language. Available alternate language
content can aid their comprehension of your message.
- Clearer, more understandable, content
- when targeting an international marketplace, using localized jargon,
idiom or culturally restricted concepts in your content may make your
message seem unfriendly or confusing. Simple, clear language and usage
will often translate more easily.
Assisting access for low-bandwidth users
Providing alternative content that is appropriate for low-bandwidth
connections is a market-increasing strategy. While affordable, available
high-bandwidth technology is becoming a reality for some Web users, by far
the majority of the world's users are limited to low-bandwidth connections
because of geographical isolation, underdeveloped communications
infrastructure, or economic limitation. Even those living in areas with
access to high-bandwidth infrastructure may still be limited to low-bandwidth
applications because of the technology they have chosen to use (such as
cell-phones, PDAs, etc.) or are forced by economic
circumstances to use (eg. older systems).
- Alternative text, "D" links and
"longdesc" attributes -many page authors want to use large images such as
photographs, charts and graphs to illustrate concepts or supplement the
content of a document. A long established technique to aid low-bandwidth
users is to provide a small (thumbnail) version that is linked to the
full-sized image. But if the bandwidth is severely restricted, a
text-based alternative will be welcomed by the user.
- Text alternatives for multimedia - a few megabytes of video or audio
media may often be summarized and described in a few thousand bytes of
text-based content. The bandwidth savings can be immense. The users,
should they choose, may download the full multimedia presentations but
are pleased to have the option of reading the alternative.
- Use of style sheets - separating stylistic
mark up and presentation from content, especially in a master style sheet
file, can significantly reduce the size of individual pages being served
across the Internet. A master style sheet file is read into the browser's
cache once and is available instantly to all pages that refer to it.
- Clear navigation - providing clear and
consistent navigation is a major benefit to users who have to utilize low
bandwidth and wait for each page to load slowly as they can get to the
information or service they require more efficiently rather than
following "blind alleys" with the associated frustration.
3. Improve Efficiency
While the previous section highlights features that will increase your
audience, the following section describes the benefits to your operational
processes and technical procedures of applying the WCAG
1.0 techniques.
Reduce site maintenance
Site development and maintenance costs are an ongoing concern for
businesses. Applying design techniques that can reduce these costs is a
strategic move. Another concern is the rapidly changing Web technology
market; are there techniques that you can apply to help you meet the
challenge afforded by these changes? The WCAG 1.0 gives
you many such techniques.
- Separating structure from presentation -
from a development and maintenance perspective most content benefits from
following some well-designed logical structure. This internal structure
makes editing or modifications easier to accomplish because the original
intent is made clearer from the inherent structure. However, it is not
always necessary or advisable (from a marketing point of view) to display
the content in the same structure as it is written. By separating
structure from presentation you are able to manipulate the content to
suit differing presentation styles without having to change the content.
This reduces the amount of coding necessary when modifications are
required.
- Style sheets vs. in-line markup - extensive use of inline
HTML stylistic techniques, or even inline style
markup, can make review and repair of code problems very time consuming.
Moving all style-related markup to style sheet files makes debugging
stylistic problems easier (since you know exactly where the offending
markup resides) and makes problems in the content files easier to locate
(because you are not wading through long strings of confusing stylistic
markup).
- Text alternatives - for people maintaining
your site there is another benefit of using text-alternatives for image,
object and multimedia content: descriptive alt-text can significantly aid
the editing, updating and quality assurance processes by identifying the
non-text content more easily. Think of text alternatives as "internal
documentation" for your Web application.
- XML and other
evolving W3C technologies - the benefits described in this document will
be realized if the concepts expressed in the WCAG 1.0
are applied to any Web application development: not just to designs using
HTML. The WAI has published papers
about the accessibility features of XML, SVG and SMIL that
make their benefits clear.
- Upgraded authoring software - authoring tools that support
WAI standards will set you up for the future with
better code requiring less maintenance.
- Device independence - Web sites adopting
this approach will require less adaptatin to create multiple version and
incur lower ongoing maintenance costs.
Site Search Engine Improvements
Clearer
content and the inclusion of alt-text with your images and other non-text
elements will assist all visitors to your site to utilize your search
facilities if they cannot locate the information or services they seek
through normal navigation means. Depending on the search
engine you employ, metadata, structural markup and multimedia captioning can
also contribute to improved resource discovery within your site. If your
customers' searching is more successful, they will not need to use more
resource-consuming technical or business support services.
Repurposing Content
The adoption of device independent practices will
enhance your ability to repurpose your content for use on the evolving range
of Web enabled devices from WAP-enabled phones to
PDAs to in-car navigation devices. Techniques include the
separation of structure from presentation, and ensuring that content
relevance and importance is not portrayed through color alone.
Address server-load
With increasing traffic on the Internet, many organizations are
discovering their server performance may not be keeping up with client
demand. WCAG 1.0 techniques can help reduce the load being
placed on your server.
- Style sheets - the use of separate, or
master, style sheets will reduce the size of the content pages that your
server has to send out; the style sheet file contains all the
presentation and layout code and will be cached locally on the requesters
local machine.
- Clear navigation - reduces circling around
looking for the desired information or service resulting in fewer HTTP
requests on your server. Including better defined & clearer links,
and the consistent use of graphics to indicate key features and
functions, will result in fewer requests to your server
- Text alternatives (alt-attribute,
longdesc-attribute, "D" links) - the inclusion of some or all of these
WCAG 1.0 techniques may encourage more of your
bandwidth or technology-challenged visitors to browse your site with
"graphics off". They will be better able to understand the nature and
purpose of any graphics and selectively request them. This will reduce
your server load as minimal numbers of your graphics files will be
requested by visitors who do not want to, or cannot, see them.
Address server-bandwidth
With increasing traffic on the Internet, server-bandwidth can also be
inadequate to meet client demand. Again, WCAG 1.0
techniques can help reduce the load being placed on your server
connections.
- Clear navigation - will assist your
visitors reach their destination more quickly, resulting in less pages
being requested over your limited bandwidth and giving the user a more
satisfying experience through better response and more quickly retrieved
pages.
- Text alternatives - with bandwidth a
limitation through technology or economic circumstances, providing a site
that at least some of your users will be happy to visit with their
graphics disabled will reduce the traffic on your internet
connection.
- Separating structure from presentation -
providing the presentation intructions for your pages in a style sheet
means that your pages will be smaller in size and impose less strain on
your limited bandwith.
4. Demonstrate Social Responsibility
Some benefits to an organization, such as goodwill from the general
public, may be less tangible than the economic or technical ones described
earlier. However, in an extremely competitive world-marketplace can any
benefits be ignored?
- Increasing the accessibility of your Web site and online services to a
wide range of people with disabilities and other disadvantaged members of
the community will reinforce your organization's socially responsible
attitude.
- All countries have significant numbers of people with disabilities -
they comprise an influential proportion of the population. The population
in many countries is also ageing, and with older age the incidence of
disabilties increases.
- Raising awareness of the requirements of people with disabilities
through the creation and promotion of an accessible Web site and
associated online services can help to influence your internal operations
and attitudes, thus creating a workplace that is more attractive and
accessible to people with disabilities.
5. Reduce Legal Liability
In many countries around the world discrimination laws require
governments, educational institutes, corporations and businesses to provide
equal opportunities for people with disabilities. This may include equal
access to electronic information and services in the same way that physical
access to facilities is required. The laws vary from country to country and a
listing of country specific laws
and policies is maintained by WAI.
Having your programmers and developers incorporate WCAG
1.0 checkpoints into your Web site design from an early stage will be more
efficient, and cheaper, than doing so after protracted legal proceedings.
Furthermore, an increasing number of industry organizations in various
countries are developing accessibility codes of practice or industry
policies.
6. Benefits Matrices
The following tables indicate the interactions between various
WCAG 1.0 checkpoints and benefits related to market reach
and technical efficiency.
![skip tables](https://webarchive.library.unt.edu/eot2008/20090115201144im_/http://www.w3.org/Icons/transparent)
YES in a cell in the following tables
indicates that we have included more information earlier in this document to
describe the business benefit of the WCAG 1.0 Checkpoint.
The YES cells are linked to the appropriate places in the earlier
text.
Market Share Benefits of Accessible Web Site
Design
Checkpoints |
Usability |
Public Search Engines |
Repurpose |
Internationalization |
Low Bandwidth |
Support low literacy |
Semantic Web |
Checkpoint Reference |
Clear Navigation |
YES |
no |
no |
no |
YES |
YES |
no |
(13.4; 13.5) |
Device
independence |
no |
no |
YES |
no |
no |
no |
YES |
(9.x) |
Clear Content |
YES |
YES |
no |
YES |
no |
YES |
YES |
(14.1; 14.3) |
Text Alternatives |
YES |
YES |
no |
no |
YES |
no |
YES |
(1.1) |
Metadata |
no |
YES |
no |
no |
no |
no |
YES |
(13.2) |
Separate Structure from
Presentation |
no |
YES |
YES |
no |
YES |
no |
YES |
(3.3; 3.5; 3.6; 3.7; 11.2) |
Captioning for Multimedia |
YES |
YES |
no |
YES |
no |
no |
no |
(1.3; 1.4) |
Color Independence |
YES |
no |
YES |
no |
no |
no |
no |
(2.1; 2.2) |
Table Attributes |
no |
YES |
no |
no |
no |
no |
no |
(5.5) |
W3C Technologies |
no |
no |
YES |
no |
no |
no |
no |
(11.1) |
Technical Efficiency Benefits of Accessible Web
Site Design
Checkpoints |
Site Search Engine |
Repurpose |
Server Bandwidth |
Maintenance |
Server load |
Checkpoint Reference |
Clear Navigation |
no |
no |
YES |
no |
YES |
(13.4; 13.5) |
Device independence |
no |
YES |
no |
YES |
no |
(9.x) |
Clear Content |
YES |
no |
no |
no |
no |
(14.1; 14.3) |
Text Alternatives |
YES |
no |
YES |
YES |
YES |
(1.1) |
Metadata |
YES |
no |
no |
no |
no |
(13.2) |
Separate Structure from
Presentation |
YES |
YES |
YES |
YES |
YES |
(3.3; 3.5; 3.6; 3.7; 11.2) |
Captioning for multimedia |
YES |
no |
no |
no |
no |
(1.3; 1.4) |
Color Independence |
no |
YES |
no |
no |
no |
(2.1; 2.2) |
W3C technologies |
no |
no |
no |
YES |
no |
(11.1) |
Alternative, linear
version of tables.
Last Updated: 24 March, 2002.
Prepared by Andrew
Arch (Andrew.Arch@visionaustralia.org.au)
and Chuck Letourneau (cpl@starlingweb.com) with assistance
from W3C/WAI's EOWG members. About
WAI: The Web Accessibility Initiative is
supported in part by Sponsors. Opinions
expressed in this document do not necessarily represent those of the
sponsoring organizations.