WCAG 2.0 Comment Submission

Name: Jason White
Email: jasonw@ariel.its.unimelb.edu.au
Document: W2
Item Number: Success Criterion 1.1.1
Part of Item: 
Comment Type: technical
Comment (Including rationale for any proposed change):
CAPTCHA: This success criterion is problematic. Even if both auditory and

visual forms are provided, the content will remain inaccessible to users who

are deaf blind. Furthermore, this lack of accessibility is not remedied at

either level AA or level AAA of guideline 1.1, there being no success criteria

at those levels.

Cognitive CAPTCHA, e.g., arithmetic problems, can overcome the sensory

difficulty noted above, while running the risk of raising barriers to people

with cognitive disabilities.

The only solution is to abandon CAPTCHA altogether, in favour of statistical

filtering, e-mail confirmation or other security techniques as the situation

demands. Given that services subject to CAPTCHA are often, from a practical

point of view, significant, the result of the unfortunate compromise in

guideline 1.1 is to exclude a significant group of users - those who are deaf

blind - from important Web content.

Proposed Change:
Either require cognitive CAPTCHA, noting that it must be designed so as to

minimize its adverse effect on users with cognitive disabilities, or,

preferably, acknowledge that the CAPTCHA phenomenon is incompatible with

accessibility, and hence incompatible with WCAG 2.0 conformance.

While a Level AA success criterion excluding sensory CAPTCHA would be a

welcome improvement to the current situation, it would still leave Level

A-conformant content inaccessible to a significant group of users. Depending

on the interpretation of WCAG 1.0, checkpoint 1.1, the current WCAG 2.0 draft

is arguably a regression in that it offers less accessibility than is

guaranteed by the 1.0 guidelines at level A, where no such limitation is


Received on Tuesday, 22 May 2007 11:12:13 UTC