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RE: Text-based Captchas

From: Mark | Carbon Chip <mark@carbonchip.com>
Date: Wed, 3 May 2006 12:28:50 +0100
To: "'David Poehlman'" <david.poehlman@handsontechnologeyes.com>
Cc: "'WAI Interest Group'" <w3c-wai-ig@w3.org>
Message-ID: <006e01c66ea4$c0156f80$0400a8c0@norris>

Hi David

Yes, I see that various user groups would not benefit, but it might have
some validity in enhancing the test offered to the user. I guess Utopia
would supply options for any/all of the following (allowing the user the
choice of which to undertake): 

1. Image.
2. Audio.
3. Knowledge (re: Matthew's suggestion).
4. Email.
5. Credit card.
6. Telephone.

A convergence of a solution yielding the above would allow developers to
base their systems on their target audience, and in the absence of any
specific demographic, implement all as required. Certainly the first four
options could be handled by a nicely bundled open source script :)


-----Original Message-----
From: w3c-wai-ig-request@w3.org [mailto:w3c-wai-ig-request@w3.org] On Behalf
Of David Poehlman
Sent: 03 May 2006 12:10
To: Mark | Carbon Chip
Cc: 'WAI Interest Group'
Subject: Re: Text-based Captchas


This leaves out huge swaths of possible site users who either do not have
sound cards or who cannot hear or hear well.  Good idea though, it would not
require someone who would beneffit from the audio to do extra work or to be

On May 3, 2006, at 6:56 AM, Mark | Carbon Chip wrote:

Has anyone done anything with Flash in conjunction with images? I started
some work on a Flash system which automatically played a Captcha audio file
that correlated with the Captcha image.

I mention Flash, not wishing to incur any wrath :), but just as an
augmentation to image based Captchas. Obviously user control isn't there,
and to hear the audio again, the user would have to refresh the page, and
invariably have a different character sequence read to them, but possible
advantages are:

1. Augmentation only, would add to image Captcha method.
2. Lack of Flash player should not impair the procedure.
3. Flash may have a benefit over serving up audio files, in that another
application would not need to be opened (eg if .MP3 served instead).
4. Very customisable - would not need to run a server side script to process
and stitch audio files together - Flash could handle this, and different
voice libraries (of higher/lower quality) could easily be added as required.


1. Surprise to user - no control, unless directed to a separate page and
informed of what is going to happen.
2. Plug-in dependent.

I hadn't seen any type of open source server-side audio manipulation tool,
and guessed that it would be quite server intensive and require privileges
that many site owners would not have, hence Flash.


-----Original Message-----
From: w3c-wai-ig-request@w3.org [mailto:w3c-wai-ig-request@w3.org] On Behalf
Of David Poehlman
Sent: 03 May 2006 11:30
To: Patrick Lauke
Cc: WAI Interest Group
Subject: Re: Text-based Captchas

I found a really interesting one at:
where you change your mailing adddress.  If you go to change address, they
have a link that will provide you with the string in the clear.

On May 3, 2006, at 4:39 AM, Patrick Lauke wrote:

> Matthew Smith

> Appropriate links are here:
> <http://www.smiffysplace.com/blog/archives/169-php-text-captcha>

Although the question are fairly simple, entailing nothing more than "common
knowledge", it's still possible that some geniune user may not know the
answer to them.

More generally, users may actually be confused by finding any sort of
question not related to the task they're trying to achieve (I want to book a
flight, why is it asking me who the President of the US is?), so this may
require a careful bit of preamble/legend, perhaps.

But regardless, nice one.

Patrick H. Lauke
Web Editor / University of Salford
Web Standards Project (WaSP) Accessibility Task Force
http://webstandards.org/ ________________________________
Received on Wednesday, 3 May 2006 11:29:03 UTC

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