W3C home > Mailing lists > Public > public-html-a11y@w3.org > March 2010

RE: keep CAPTCHA out of HTML5

From: John Foliot <jfoliot@stanford.edu>
Date: Wed, 17 Mar 2010 14:34:26 -0700 (PDT)
To: "'Silvia Pfeiffer'" <silviapfeiffer1@gmail.com>
Cc: "'Gregory J. Rosmaita'" <oedipus@hicom.net>, <public-html-a11y@w3.org>
Message-ID: <02e501cac619$9e277af0$da7670d0$@edu>
Silvia Pfeiffer [mailto:silviapfeiffer1@gmail.com]
> Very interesting indeed. It seems to indeed be a big accessibility
> challenge.
> Do images get transferred onto braille at all? Could it be done
> pixel-wise? I'm wondering if there could be a technical solution, even
> if it doesn't exist yet.

I've seen some interesting experiments with tactile processing of maps,
etc., but the detail is also limited in some ways due to the amount of
visual data required to be conveyed. Most of those experiments relied on
some basic form outline's over-laid with image-map like area data. In
situations such as where we normally see CAPTCHA's used that additional
data would likely not be provided by the author.

The problem with any kind of OCR-like solution here is that it is a race
to the bottom - if OCR does get better, CAPTCHA's will continue to get
increasingly complex to frustrate that improvement - a vicious circle with
no end in sight. At some point, the CAPTCHAs also become increasingly
difficult for sighted users to negotiate, further frustrating your user
base.  The foundation of the solution is flawed, thus any implementation
of that solution will also be flawed: being able to discern what a series
of glyphs represent does not represent cognition, which is what CAPTCHAs
are trying to determine (man vs. machine).

I personally hold out more help for distributed authentication schemes
such as OAuth, etc. which requires a one-time determination of
'authenticity' of your human-ness, after which you have a social key that
can be used inter-changingly. We are already starting to see solutions
like this emerge, where you can 'log-in' to locations using your FaceBook
account, G-Mail account, your twitter username etc.

Establishing disabled-user support groups as CA like entities could help
here (for example, the RNIB could assist non-sighted users in the UK by
confirming them with an OAuth profile, which they then could use) -
ultimately what we have here (I believe) is a social issue, which will
require a social solution

Received on Wednesday, 17 March 2010 21:35:00 UTC

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