Best Practices
for Designing Accessible
Websites, Software and Content
Although
including the items
on this list will go a long
way towards making your
websites,
software and course
materials
accessible, this is not meant
to take the place of
a thorough review.
Always verify that your
sites and course materials
comply with Section 508
regulations and W3C (World
Wide Web Consortium) WCAG
(Web Accessibility Content
Guidelines)1.0 Priority
One and Two recommendations,
and that they validate to
XHTMLl 1.0 Transitional
code, before making
them available to the University
of Michigan community. This
will help make your materials
accessible to students with
disabilities and show
"Good Faith" effort
in meeting their needs under
the Americans with Disabilities
Act (ADA) and (where applicable)
Sections 504 (software applications)
and 508 (websites). For
assistance, please contact
Scott Williams, at swims@umich.edu. Resources
are provided at the bottom
of the page.
Accessible Websites and Software
In general,
Adaptive Technology (AT)
users should be able to
use your site or software
without a mouse (using the
keyboard only). Including
the below items will help
persons with disabilities
adjust your site to their
needs and utilize AT shortcuts.
-
Use Cascading Style
Sheets (CSS)
for website
presentation and, when
possible, positioning.
For presentation, this
includes font size,
color, style; behavior
(such as mouseover or
focus); borders; padding;
margins; background; etc.
For positioning this includes:
distance from top and
sides; x, y and z axis;
etc. If you use a table
for page layout, make
it a simple layout, without
nesting.
-
Use
relative elements
like "percentage" or "em"
instead of "pixels." Common
instances include font
sizes, table layouts,
and css-based positioning.
- Use the <alt> attribute
to describe images. Images
that contain information
relevant to understanding
the purpose or providing
context to the page should
have a description. Images
that do not provide information
or context should have
<alt="">.
- Use <h1, h2,
etc.> tags
to chunk page content
under headings
and for links to key content
areas. Heading tags will
not only provide context
for screen reader users,
but enable them to skim
through a page.
- Follow WCAG 1.0 guidelines
for forms.
For example, associate
labels with input boxes
(<label for> and <id>
tags) and group related
parts of a form using
the <fieldset> and <legend>
tags.
- Follow WCAG 1.0 guidelines
for tables.
For example, include summaries
and captions for data
tables, and associate
column headings with data
using the <scope> attribute.
- Provide keyboard-based
navigation through
the site using accesskeys
and skip links. For example.
provide accesskeys to
Accessibility Information
about the site (0), Home
(1), What's New (2), Site
Map (3), Search (4) and
Content (C). Provide skip
links from the top of
the page to Main Content
and other key areas of
your site.
- Use meaningful text
for links. AT users tab
through sites, listening
to links for context.
Links should therefore
have text that clearly
identifies their purpose
or destination, to make
sense without the surrounding
text.
- Add the <title> attribute to links and frames. Titles
should provide additional
information not otherwise
available in link text.
Frame titles can be used
for navigation.
-
Use
color properly.
Do not rely only on color
to differentiate items
in your site. For example,
persons who are colorblind
cannot distinguish
between green and red,
so highlighting text in
red will not be helpful.
Also, make sure there
is sufficient contrast
between background color
and items in the foreground,
such as buttons and text,
so that people with compromised
vision will clearly see
them as separate.
-
Caption video.
Provide captioning for every
video that you provide online.
MAGpie (http://ncam.wgbh.org/webaccess/magpie/magpie2_download.html)
is an excellent, easy to
use tool for captioning
WindowsMedia, RealPlayer
and QuickTime files.
Accessible
Course Materials
In general,
the best way to create course
materials is to first format
documents within the application,
as if you are formatting
a web page, and then save
them into html using a converter
like the
Web
Publishing Accessibility
Wizard (www.rehab.uiuc.edu/ppt/install.html).
-
Add
text to images.
In Microsoft Word and
PowerPoint, click on the
picture, then go to: Format > Picture
> Web. Add a description
for the image in the textbox.
In Adobe Acrobat, open
the PDF file
-
Format
text.
In Microsoft Word, apply
formatting to document
titles, headings and lists.
Highlight the text, then
go to: Format > Styles
and Formatting > Choose
"All styles" in
the "Show:"
dropdown box > click
on the format you need.
In PowerPoint, use slide
titles to describe page
content, since they will
appear as a table of
contents when you convert
the document to html.
-
Create
tables and charts.
Be sure to create tables
and charts within the application,
rather than copying them.
This will preserve the integrity
of the underlying data,
and enable the Wizard to
make them accessible.
-
Convert
document. Install
the Web Publishing Accessibility
Wizard on your computer.
It will insert "Save
As Accessible Web Page" under
"File" in Microsoft
Word, PowerPoint and Excel.
To save your document in HTML,
go to File > Save As
Accessible Web Page, then
follow the step by step
directions to describe
charts, graphs and/or
tables.
Accessibility
Resources
A variety
of tools are available for
verifying
compliance and
validating
code. The paper
books,
electronic
books, research and websites
contain useful information
about designing accessible
websites and software.
For additional resources,
see the Resources page on the "Online Accessibility" website
(www.umich.edu/~webacces/Resources.html).
Verifying
Compliance
A variety of tools are available to evaluate how well
a website complies with accessibility standards.
-
A-Prompt™ (aprompt.snow.utoronto.ca/).
A-Prompt™ is
a Windows-based
accessibility tool
developed by the
University of Toronto
and the University
of Wisconsin. A-Prompt
evaluates websites
based on the W3C's
Web Accessibility
Guidelines version
1.0 and can be downloaded for
free. A French language
version was released
in 2002.
- Bobby™ (bobby.watchfire.com/bobby/html/en/index.jsp).
Bobby™ will
evaluate a site
for W3C guidelines
or Section 508 regulations
and is probably
the best known evaluation
tool. Bobby indicates
when a code guideline
has been violated
(with Bobby hats)
and recommends manual
checks for items
it cannot verify
(question marks).
It also provides
links to the relevant
Section 508 requirement
or W3C guideline,
which contain examples
of code. You are
limited in the number
of pages that can
be checked at a
time (which is a
bother), although
Bobby 5.0, an unlimited
version, can be downloaded (www.elicense.com/watchfire/store/index.asp)
for $299.
- Macromedia
Dreamweaver
™ (http://www.macromedia.com/software/dreamweaver/).
A very useful web
development tool that has
built-in accessibility and
validation checkers. Be sure
to check all "Show Attributes
When Inserting" boxes under
Edit > Preferences, so you
will be prompted for accessibility
tags and elements when you
design pages.
- Vischeck
™ (www.vischeck.com).
The Vischeck™ website
checks readability
of websites, or
images with
respect to color
blindness.
- AIS
Web Accessiblity
Toolbar for
Internet Explorer
(http://www.visionaustralia.org.au/info.aspx?page=614).
A comprehensive
add-on for Internet
Explorer for
evaluating and
validating web
pages. Highly
recommended.
Validating
Code
Here
are several tools,
in addition to Macromedia
Dreamweaver (mentioned
above), that validate
htm/xhtml/css code.
Paper Books
These
books provide information
about how to produce
both usable and accessible
websites.
- "Accessible
XHTML and CSS
Web Sites: Problem
- Design - Solution," Jon
Duckett, Wiley Publishing,
2005
- "Building Accessible Websites," Joe Clark,
New Riders, 2003
- "Maximum Accessibility, Making Your Web
Site More Usable for Everyone," John M. Slatin and Sharron Rush,
Addison-Wesley, 2003
Electronic Books
The following usability and accessibility resources can
be downloaded from the Internet.
Research
- "Beyond ALT Text: Making the Web Easy
to Use for Users with Disabilities," Kara Pernice Coyne and Jakob
Nielsen, 2001
- "How to Conduct Usability Evaluations
for Accessibility," Kara Pernice Coyne and Jakob Nielsen, Nielsen
Norman Group, 2001
- "Research-Based
Guidelines on
Web Design and
Usability Issues," Sanjay
J. Koyanl, Roert
W. Bailey, Janice
R. Nall, National
Cancer Institute (http://usability.gov/pdfs/guidelines.html#1)
Websites
- W3C
Web Accessibility Initiative (http://www.w3.org/WAI/), especially
"Getting
Started: Making a Website Accessible" (http://www.w3.org/WAI/gettingstarted/)
- Knowbility
Training Guide
for Austin Accessibility
Internet Rally
(AIR)
(http://cookiecrook.com/AIR/2003/train/).
A concise and
thorough tutorial
on making websites
accessible by
members of the
Austin, Texas
accessibility
community. It
was developed
in support of
the Accessibility
Internet Rally,
an annual event
in which web
designers create
accessible websites
for non-profit
organizations,
while competing
for prizes and
recognition. Knowbility (http://knowbility.org/index.jsp),
an accessibility
organization
in Austin, Texas,
sponsors AIR.
The Knowbility
website contains
much useful
accessibliity
information
as well as links
to winning AIR
websites.
- Zen Garden (http://www.csszengarden.com/).
A lovely website
that shows how CSS
can be used to create
compelling design.