We've had good experience with the "Detect content within a hidden form element" technique mentioned in the WebAIM article. If the field has any content we just reject the submission with a notice that they need to empty the field.

Since spambots don't always enter every field, you can increase the effectiveness of this technique by using multiple fields -- three of them are enough to reject almost every automated spam submission.


----- Original Message -----
From: "Peter Wiringa" <[log in to unmask]>
To: [log in to unmask]
Sent: Monday, November 2, 2009 12:17:48 PM GMT -06:00 US/Canada Central
Subject: Re: [CSS-DEV] captcha anyone?

Here are some approaches that should help to reduce form spam 
without introducing accessibility problems.


Also, if it's an internal-only form that doesn't purport to take in 
confidential responses, you could always add cookieauth to it, so 
users are forced to login. Yes, it *could* be an extra step for your 
users, but it's the simplest approach I know of, if you don't 
already have a set of form handlers you can use.

Jake LaSota wrote:
> Hi all,
> I've got a form that's receiving a bunch of ugly automated submissions. 
> Does anyone know of a good captcha code/plug-in?
> I've found a few, but I'm sure there's something better floating around 
> out there.
> Perhaps there's a better technique than using a captcha to stop these 
> submissions?
> Thanks,
> Jake

Peter Wiringa
Electronic Communications
University Relations
University of Minnesota
(612) 625-3252
[log in to unmask]

"I gotta hold on to my angst. I preserve it because I need it. It 
keeps me sharp, on the edge, where I gotta be." - V. Hanna