Technique G144:Ensuring that the Web Page contains another CAPTCHA serving the same purpose using a different modality

Applicability

Applies to all technologies.

This technique relates to 1.1.1: Non-text Content (Sufficient, together with G143: Providing a text alternative that describes the purpose of the CAPTCHA).

Description

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.

Examples

• 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 visual 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.

Related Techniques

• G143

Tests