Adobe Flash Professional CS3 - Manual (Page 485)

FLASH CS3
User Guide
479
Accessibility guidelines
About accessibility guidelines
Screen readers are complex, and you can easily encounter unexpected results in FLA files developed for use with
screen readers, which is software that visually impaired users run to read websites aloud. Text is read aloud using
specially designed software. A screen reader can only interpret textual content. However, any descriptions that you
provide for the overall SWF file, movie clips, images, or other graphical content are also read aloud. Write descrip-
tions for the important images and animations so that the screen reader can also interpret these assets in your SWF
file. This is the SWF file equivalent to alt text in an HTML web page.
Note: Flash applications must be viewed in Internet Explorer on Windows, because Microsoft Active Accessibility
(MSAA) support is limited to this browser.
Flash Player uses Microsoft Active Accessibility (MSAA) to expose Flash content to screen readers. MSAA is a
Windows-based technology that provides a standardized platform for information exchange between assistive
technologies, such as screen readers, and other applications. Events (such as a change in the application) and objects
are visible to screen readers by using MSAA.
Note: Flash Player 7 (and later) does not work with all screen-reader technologies. The third-party software provider
must handle the information that MSAA provides.
Creating accessible sites
Making a website accessible involves several different criteria:
Expose the information to screen readers Make text or images realizable Some visitors might have difficulty
reading small text or seeing small graphics. Allow users to zoom in on these elements, taking advantage of scalable
vector graphics in SWF files.
Provide audio narration Consider providing an audio narration for visitors without a screen reader, or where screen
readers might not work, such as with video content.
Provide captions for audio narrations Some visitors might not be able to hear an audio narration for your site or a
video. Consider providing captions for these visitors.
Do not rely on color to communicate information Many visitors might be color blind. If you rely on color to commu-
nicate information (such as: Click the green button to go to page 1, click the red button to go to page 2), provide text
or speech equivalents.
Historically, many online presentations (such as videos) provide alternative ways for visually impaired visitors to
access the content, for instance, a textual description of a video. However, Flash provides textual information directly
to the screen reader. Although this usually means you need to make additional settings or ActionScript in a FLA file,
you do not have to create a completely separate version.
Parts of your SWF file can be exposed to screen readers. Text elements (such as text fields, static text, and dynamic
text), buttons, movie clips, components, and the entire SWF file can be interpreted by MSA-compliant screen
readers.
Section 508 is United States legislation that provides guidelines for making information accessible to people with
disabilities. Section 508 specifically addresses the need for websites to be accessible in several ways. Some websites,
including all federal websites, must comply with these guidelines. If a SWF file does not communicate all of the infor-
mation to the screen reader, the SWF file is no longer Section 508-compliant. For more information, see the Section
508 website.