Last Modified: July 31, 2002
Introduction
Below are some useful tips and links that can help to
make your site accessible by
all browsers, and better in general. This is not meant to be
a complete guide to HTML, just a look at web design from an
accessibility point of view. I
have tried whenever possible to provide links to sites with
more indepth information than what is here- please let
me know of any sites that would enhance the usefulness
of any of the sections below, or if I have missed any
important topics in accessibility.
Remember when reading this page that the advice provided
is as general and thorough as possible to make it the most
useful to the most readers. When enhancing the accesibility
of your site, make sure to consider any special needs of
your site, as well as the intended audience and available
time and skill. The more you do to make your site accessible,
the better, but if you can't follow all the recommendations,
at least do what you can to follow those that make sense to
your needs.
If you don't know enough HTML to make sense of the advice
here, and you're looking to learn, there are plenty of links
to excellent HTML guides available from About.Com's
HTML section.
Contents
Key Terms
Accessibility
In the context of web site design, accessibility is a
measure of how easy it is to access, read, and understand
the content of a web site. Accessibility is complicated by
the fact that a web site is not a published piece of work so
much as a living document that can be interpreted in
different ways by different browsers and on different
platforms. Web sites are not a print medium- although they
are most often read in a visual manner, there are many
different ways a web page can be experienced, such as via a
speech browser or via an indexing robot. A web page is a
combination of textual information which is interpreted
appropriately by a browser and linked to files of various
types, such as graphics, movie clips and sound files.
Since a web page can be interpreted differently by
different browsers with different capabilites, and since the
language of a web page- HTML, is constantly evolving,
accessibility must be considered to make a page usable by as
many people as possible. The keys to making your page
accessible are graceful
degradation, standards compliance, fast loading, and
intelligent organization.
Graceful
Degradation
Since HTML is continually changing and different browsers
support different elements, graceful degradation is the key
to making sure that pages are readable and accessible
in all browsers. When a browser encounters tags it doesn't
understand or can't display, degradation takes place.
Whether this degradation will cause some of your page
content to be lost to the browser, or whether the content of
your page can still be accessed fully is dependent on
whether the degradation is graceful.
The HTML standards were written with graceful degradation
in mind- new attributes to older tags are safely ignored so
that the rest of the tag can still function normally, and
new tags are written with alternative display for browsers
that don't support them in mind. There are many elements of
HTML that can't be displayed or can be turned off in
browsers that were written with the knowledge of these
elements- such as images, java, and frames. Using the
appropriate methods to provide an alternative message to
those who can't see those elements or have turned them off
is one way to design for graceful degradation.
If you design pages with graceful degradation in mind, by
utilizing the built in elements of the HTML standards, and
the advice provided here, you can design pages that should
degrade gracefully in all browsers and are accessible.
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Section (Design Elements)
Accessible Design Guide: Introduction
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Key Terms |
Design Elements |
Testing and
Considerations | Accessible
Design Tools
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