Yep. It works on the production system too.

Took me blody seven tries to post this comment! 8-)

I'd suggest adding a little space between some of the math words. I bet that humans will have an easier time joining the meaningful words than bots.

What is two min us one?

You could even do a thin space (or something) to screw stuff up :-)

Uh. three times one isn't banana?

Nice.

btw, Google gets you a lot of the way: "seven plus seven"

No, Brian. What did they teach you in grade school? Everyone knows that nectarine divided by kiwi is banana. Sheesh!

But would "seven" also work?

neat! It could be a bit clearer as to how to respond and you could also provide the option to write a word as the answer. If I am to input a digit or two digits, it needs to be clearer that that is what I am being directed to do because screen readers do not differentiate in sound between 7 and seven or 14 and fourteen the latter may actually work but not usually.

Interesting to see one of the ads that appeared alongside this offering "grade 'A' term papers - for as little as $10/page". I guess that gives a clue about how the world really works...

I'd love to see some ongoing reporting of how well this works. I guess one of the problems is that the faster people make use of the protection technique the moreincentive there is for spammers to figure out the workaround :(

Still, better than the picture ones. I am pretty sure automated cracking of those has already got better than me.

Possible answers:
40
forty
a multiplication fact

This question suffers from the ususal forms malaise. Guessing what the author assumes is the obvious information type and format for the answer is a greater cognitive challenge than the simple math fact that is intended as the shibboleth, the discriminant between bots and walk-on people. So a VoiceXML <form> is a better match to the task than an HTML <input>.

Fine, fine, fine! English language answers now work! Y'all can write seven and fourteen and forty if you're so inclined. Me, I'm going to stick with 7 and 14 and 40.

This isn't nearly as fun as Hot or Not CAPTCHA.

*Snort* I can't decide if that's more amusing than offensive or vice versa.

Adding a comment won't work if I've clicked on a link to another part of the page, like from this

http://norman.walsh.name/2006/06/30/captcha

to this

http://norman.walsh.name/2006/06/30/captcha#p4

Oops. Fixed. Thanks for letting me know.