Visual Basic.NET How to Program (PDF)

Chapter 24 Accessibility 1209
browser “reads” text that the user selects, allowing the user to control the speed and volume
at which the browser reads the contents of the Web page. The WeMedia Browser free
download is available at www.wemedia.com.
IBM Home Page Reader (HPR) is another browser that “reads” text selected by the
user. The HPR uses IBM ViaVoice technology to synthesize an audible voice. A trial version
of HPR is available at www-3.ibm.com/able/hpr.html.
24.5 Maximizing Readability by Focusing on Structure
Many Web sites use XHTML tags for aesthetic purposes, ignoring the tags’ intended functions.
For example, the heading tag often is used erroneously to make text large and
bold rather than to indicate a major section head for content. This practice might create a
desired visual effect, but it also causes problems for screen readers. When the screen–reader
software encounters the tag, it might verbally inform the user that a new section has
been reached. If this is not in fact the case, the tag might confuse users. Therefore,
developers should use h1 only in accordance with its XHTML specifications (e.g., to markup
a heading that introduces an important section of a document). Instead of using h1 to
make text large and bold, developers can use CSS (Cascading Style Sheets) or XSL (eXtensible
Stylesheet Language) to format and style the text. For further examples of this nature,
refer to the WCAG 1.0 Web site at www.w3.org/TR/WCAG10. [Note: The
tag also can be used to make text bold; however, screen readers emphasize bold
text, which affects the inflection of what is spoken.]
Another accessibility issue is readability. When creating a Web page intended for the
general public, it is important to consider the reading level (i.e., level of difficulty to read
and understand) at which content is written. Web-site designers can make their sites easier
to read by using shorter words. Furthermore, slang terms and other nontraditional language
could be problematic for readers from other countries, and developers should limit the use
of such words.
WCAG 1.0 suggests using a paragraph’s first sentence to convey its subject. When a
Web site states the point of a paragraph in its first sentence, it is easier both to find crucial
information and to bypass unwanted material.
The Gunning Fog Index, a formula that produces a readability grade when applied to
a text sample, can evaluate a Web site’s readability. To obtain more information about the
Gunning Fog Index, visit www.trainingpost.org/3-2-inst.htm.
24.6 Accessibility in Visual Studio .NET
Visual Studio .NET provides guidelines for the design of accessible software within its programming
environment. For instance, one guideline recommends reserving the use of color
for the enhancement or emphasis of information, instead of for aesthetic purposes. A second
guideline recommends providing information about objects (e.g., desktop icons and
open windows) to the accessibility aids (specialized software that renders applications to
individuals with disabilities). Such information might include the name, location and size
of a window. A third guideline recommends designing user interfaces so that they can accommodate
user preferences. For example, people with visual disabilities should be able to
modify the font size of a user interface. A fourth guideline recommends allowing users to
adjust the time setting for applications that have time constraints. For example, users with