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Re: Captcha and inaccessiblity

From: Marja-Riitta Koivunen <marja@w3.org>
Date: Sun, 19 Oct 2003 15:06:34 -0400
Message-Id: <>
To: Tom Croucher <tcroucher@netalleynetworks.com>, "w3c-wai-gl@w3.org" <w3c-wai-gl@w3.org>

At 03:26 PM 10/18/2003 +0100, Tom Croucher wrote:

>I forget to mention the address of the CMU project http://www.captcha.net/
>On Sat, 18 Oct 2003 15:18:23 +0100, Tom Croucher 
><tcroucher@netalleynetworks.com> wrote:
>>Captcha stands for "Telling Computers and Humans Apart (Automatically)". 
>>It most commonly involves using an image with warped text in it to 
>>'verify' that it is a human and not a robot submitting a form on the 
>>internet. However the problem is that currently all the systems rely on 
>>putting a piece of information in form which computers cannot interprete 
>>and asking a human to repeat it back. This is becoming more widely used, 
>>yahoo uses it to verify mail being sent, network solutions use it to stop 
>>third parties piggybacking on their whois lookup system. With spammers 
>>and other service abusers so prevelent the big service providers are keen 
>>to protect themselves but obviously this has impacts on accessibility.
>>I spoke to the guys at CMU about some stuff I was interested in with text 
>>based captchas a while back (6mo maybe) and they said they were working 
>>on a text version. This would probably take the form of a question which 
>>is common knowledge or analogic. ie, "If I have five apples and I eat 
>>three. I give one to Bob but Susan gives me two apples, how many apples 
>>do I have?". To which the acceptable answers would be "3", "three", "3 
>>apples", "three apples". Another example might be like those IQ tests "A 
>>dingy is to ship as a go-cart is to a?". The acceptable answers being 
>>"Car", "Bus", "Lorry" etc.

I did not know what a dingy is :-).
We don't want to filter non-native English speakers and users with 
cognitive disabilities either.

>>The other obvious way to go would be audio, so generate a word in an 
>>audio format or some other sound. So, "What animal makes this sound?" 
>>stuff like that. Which is almost inevitabley easier than finding a way to 
>>generate textual questions which are understandable enough to humans, but 
>>obscure enough to Natural Language Processors and Cognitive engines, 
>>without being so long and convulted they are obnoxious to use.
>>Some vague thoughts and possible solutions. I would love to hear ideas 
>>people have on ways we could make this work without the currently 
>>inaccessible images. I think we should insist that if people must use 
>>image Captcha they either also provide audio ones or a phone number that 
>>people can use to a bypass code.
Received on Sunday, 19 October 2003 22:54:59 UTC

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