On 9/19/05, Robbie Carlton <robbie.carlton / gmail.com> wrote:
> But they stop the average spambot, which is what they're for I think.
> The simplest accessible alternative would be email verification, but this
> obviously slows the whole thing down.
> Has anyone thought of an accessible alternative that can be embedded on the
> page?

Two things. First, they don't work against the average spambot of 2005
or later. The average spambot of 2005 has gocr or something like that
built in. (I'm using spambot because that's what you're using; what
you're talking about is actually crawlers and registration bots.) The
problem with CAPTCHA systems is that something complex enough to
defeat a computer OCR system will be enough to lock out a significant
portion of your potential users. Second, a lot of people *have*
thought about it. I'm unimpressed with most solutions.

http://www.standards-schmandards.com/index.php?2005/01/01/11-captcha
http://www.petefreitag.com/item/376.cfm
http://www.w3.org/WAI/intro/captcha.php
http://www.bestkungfu.com/archive/date/2005/01/captcha-state-of-the-union-2005/
http://www.bestkungfu.com/?p=445

Basically, my advice is to forget CAPTCHA and go with double
verification. You can even provide multiple levels of user
accessibility, allowing immediate access but nothing that could be
construed as spam until they have verified their identity in some way
that is accessible.

-austin
-- 
Austin Ziegler * halostatue / gmail.com
               * Alternate: austin / halostatue.ca