Before you even get to whether the content of these sites is accessible, you need to get past the inaccessible elements of the sign-up process. All the Web 2.0 sites that were reviewed for this article require users to sign up, and all use a method called CAPTCHA (completely automated public Turing test to tell computers and humans apart) to verify that you are a human, not a computer. A CAPTCHA is a small graphic that contains text, numbers, or both. You are asked to type the characters that are displayed into a text field. CAPTCHAs are basically a Web 1.0 technology that is used to prevent automated systems, such as those used by spammers, from signing up for services.
Unfortunately, because they are graphic, CAPTCHAs are completely inaccessible. Some CAPTCHAs include an audio alternative, but because of voice-recognition technology, the quality of the audio is poor on purpose. Anyone with less-than-perfect hearing or with auditory-processing problems would find them difficult to use.
Sherita Locklear on 28 Jan 12In several recent online and offline discussions on comment spam and other automated, improper use of forms, I have seen or heard people suggest using image-based CAPTCHAs (you know, those images of distorted letters and numbers) to prevent spambots and other programs from successfully submitting forms. Requiring the user to interpret an image of distorted characters and then enter those characters into a text input field may seem like a nice idea at first. Deciphering those characters for verification can be confusing for most of us, but for the blind who depend on screen readers, it is impossible for those programs to intrepret such mumbo jumbo.
