This is an old draft. The published version of this document is at www.w3.org/WAI/bcase/.
Business Benefits of Accessible Web Design
This is an old draft. The published version of this document is at www.w3.org/WAI/bcase/.
Note: This document is an initial draft
[see change log
in progress] and should not be referenced or quoted under any circumstances.
This document is under development by the
Education and Outreach Working Group
(EOWG), and will be offered to other
W3C groups and the public
for review in due course.
-
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 supports
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.
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 |
YES |
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.
Prepared by Andrew
Arch
(Andrew.Arch@visionaustralia.org.au)
and Chuck Letourneau
(cpl@starlingweb.com) with invaluable
assistance from members of the
EOWG.
Last Updated: 24 August 2001
Copyright © 2001 W3C
(MIT,
INRIA,
Keio ), All Rights Reserved. W3C
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