User Guide

130 Chapter 3: Using Best Practices
Creating accessible sites
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.
Making a website accessible involves several different criteria:
Expose the information to screen readers Use the techniques outlined in this section to
expose parts of your SWF files 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 communicate 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.
Section 508 is legislation in the United States that provides guidelines for making information
accessible to people with disabilities, such as vision impairments. 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 information to the screen reader, the SWF file is no longer Section 508-compliant. For
information on Section 508, see www.section508.gov.
Historically, many online presentations (such as videos) provide alternate ways for visually
impaired visitors to access the content. An example of this would be 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 MSAA -compliant screen readers. The following sections discuss how to work with
Flash and screen readers.
For more information on Accessibility and web standards, see: www.w3.org/WAI/. These
standards and guidelines do not offer much assistance when working with Flash content, but
describe what factors you must address when you create accessible HTML websites, and some of
this information applies to Flash.