Applies to all technologies.
This technique relates to:
The purpose of this technique is to reduce occasions in which a user with a disability cannot complete a CAPTCHA task. Because there are alternate CAPTCHA tasks that use different modalities, a user is more likely to be able to complete one of the tasks successfully.
A Web page that includes a CAPTCHA test that must be completed successfully before the user can advance to the next step in a process. The page includes both a visual task, such as typing words displayed in a image, and an audio task, such as typing letters spoken in an audio file. A user with hearing disabilities who cannot pass the audio CAPTCHA may be able to pass the video CAPTCHA.
A blog comment form includes a visual CAPTCHA that must be completed before a user can submit comments. In addition to the visual CAPTCHA, it includes a CAPTCHA with a form field that asks, "What is two plus seven?" with a text entry field that allows users to enter the correct answer.
For each CAPTCHA in a Web page
Check that the Web page contains another CAPTCHA for the same purpose but using a different modality.
Check #1 is true.