Just as it is important to test the general usability of your software, it is a good idea to test how well it provides for accessibility. There are a variety of ways of doing this. One way is to include users with disabilities in your prerelease or usability test activities. In addition, you can establish a working relationship with companies that provide accessibility aids. Information about accessibility vendors or potential test sites is included in the Bibliography.
You can also try running your software in a fashion similar to that used by a person with disabilities. Try some of the following ideas for testing: