On 11/2/05, David Gerard dgerard@gmail.com wrote:
Does anyone have or know of *actual data* (rather than hypothesis or anecdote) on whether non-visual captchas are any good as yet?
Anecdote, again, but it is a success story: when we launched CAPTCHAs on LiveJournal which included audio support, we got a surprising response of thank-you letters from blind users (maybe two or three, which is pretty significant in comparison to the feedback about other features...).
One way to look at it is: with a visual CAPTCHA, a blind user is completely out of luck. So even with awful usability, it's better than nothing.