[thelist] CAPTCHA

Gersten, John JGERSTEN at lchb.com
Mon Jun 8 11:45:00 CDT 2009

We looked into captchas and ended up taking a different approach as well. Among other reasons, a notable proportion of our respondents are elderly, and we were worried about adding an additional hurdle for the visually challenged and/or non-computer-literate via a captcha. 

Ultimately, we decided to eschew a captcha and instead test the form inputs for URLs. If the strings "http" or "https" appear in a form field, the form returns an error notification and the user is directed to resubmit without any URLs in any fields. (We also warn visitors at the top of each form that URLs are not allowed).

This has reduced our form spam to almost zero, and not a single user has complained about not being able to send us URLs. That said, this approach works for us because the nature of our business is such that our visitor pool doesn't really need to ever send us URLs. And we advise visitors that should they absolutely need to share a URL with us, they are welcome to call.

-----Original Message-----
From: thelist-bounces at lists.evolt.org on behalf of Sarah Adams
Sent: Mon 6/8/09 9:32
To: thelist at lists.evolt.org
Subject: Re: [thelist] CAPTCHA
>> I've been using simple humanising questions: Is water wet or dry?
> That's what I use also.  Did a lot of research before deciding on that
> solution and it's very effective, easy for the users to understand and
> quick to implement.

Another simple solution, which may or may not work in your case, is to
add a hidden field to the form which is meant to remain empty. Since a
lot of bots will automatically fill every field with garbage, you'll
know that if that field has a value that it was submitted by a bot.

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