BPOW: Alt text is for more than just screen readers
You’re probably all familiar with the use of alt text on images. It’s what a screen reader will read out to someone when it encounters that image on the page. That alt text acts as a call to action when the image is part of a link—it’s what makes people click.
Alt text is important for OTHER users of assistive technology as well. One example is voice recognition technology such as Dragon Naturally Speaking. One of the most basic principles of interaction via voice is “See it and say it”—i.e., users will see something in an interface and then say what they want to do with it.
For example, someone might say “Click Contact Us” to activate the following link on the page.
Look at the alt text:
That alt text may make reasonable sense to someone using a screen reader, but that alt text doesn’t match the visible text and makes that link useless in the “See it and say it” model of Voice interaction.
You must make sure the alt text matches (at least partially) any visible text on images, particularly for active images—those that are links or buttons. Why? Because voice recognition users will be seeing it and saying it.