Graphics Programs Reference
In-Depth Information
Considering Accessibility Issues
The Web is a public venue used by a variety of people, including people with disabilities.
You will want to consider making your site accessible to them. With regard to Web design,
accessibility
refers to the quality and ease of use of a Web site by people who use assis-
tive devices or people with disabilities. An
assistive device
is an apparatus that provides a
disabled person with alternate means to experience electronic and information technolo-
gies. Some ways that you can enhance the accessibility of a Web site include providing
alternate text descriptions for any graphics on the site that can be read by audio assistive
devices and establishing basic text links in addition to graphical navigation structures.
Effective June 21, 2001, Section 508 of the federal Rehabilitation Act requires all
United States federal government agencies, as well as public colleges and universities, to
make their electronic and information technology accessible to people with disabilities.
Although private companies are under no legal obligation to make their sites acces-
sible, many try to ensure that their sites are at least partially in line with current federal
guidelines. Because technologies change rapidly, the Web is the best source for current
accessibility guidelines and accessibility-checking tools. You can fi nd information about
accessibility guidelines on the Section 508 Web site,
www.section508.gov
.
Adobe offers a number of tools to help you develop accessible Web sites, includ-
ing templates and checking utilities. Search the Adobe site,
www.adobe.com
,
using
the keyword “accessibility” for information. You can also activate Accessibility dialog
boxes within Dreamweaver so that every time you insert an object into a Web page,
Dreamweaver prompts you for the information you need to add accessibility.
The World Wide Web Consortium (W3C) also provides information about accessibility
technology, guidelines, tools, education and outreach, and research and development.
It has created a Web Accessibility Initiative (WAI) whose mission is to promote usability
of the Web for people with disabilities. For more information, go to the WAI page on the
W3C Web site,
www.w3.org/WAI
.
For now, Gage wants to adjust the new Web site design for accessibility without chang-
ing the site's look and feel. This will make the site available to as wide an audience as
possible while maintaining a look and feel that appeals to the target audience. Gage plans
to implement basic accessibility modifi cations into the design for the new Web site, and
then create a parallel site next year that will meet all the current accessibility guidelines.
Based on a review of the current guidelines, Gage has decided to include alternate
text descriptions for graphics, graphic links, and multimedia content. This alternate text
can be “read” by audio assistive devices. Depending on the browser, this information
will appear in place of a graphic or when the user points to an image or link. Gage wants
to make the alternate text as descriptive as possible so that anyone can appreciate the
site content even without seeing it.
Audio assistive devices can
read page elements such
as page text, headers,
captions, and the page
title, but not graphics,
links, image maps, table
data order, text displayed
as graphics, buttons, mov-
ies, and sound.
Selecting Colors
Color is an interesting component of design because it affects the emotional response
that a user has to the site. The colors you choose set the tone of the site. Before select-
ing colors for a Web site, you will need a basic understanding of how color applies to
Web design.
The two major systems of color are subtractive and additive. The traditional
subtractive color system
uses cyan, magenta, and yellow as its primary colors; all other
colors are created by mixing these primary colors. It is called the subtractive color
system because new colors are created by adding pigment, such as ink and paint, and
removing light. If the primary colors of the subtractive color system are combined in
equal amounts, they make black—the absence of light. The
additive color system
uses
red, green, and blue as its primary colors. This system is also called the
RGB system
for
red, green, and blue. As with the subtractive color system, all other colors are created by
combining these primary colors. It is called the additive color system because it works
like a prism—new colors are created by adding varying amounts of light. If all of the
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