31–40 of 238 posts
Makes me wonder what sort of social engineering opportunity this creates. What other fields could be advanced in a similar way.
It's easy to criticize captchas. That's why there are so many articles like this, which we all knowingly nod along to as we read. It's much harder to provide productive criticism that leads to an actual improvement over the status quo. (Although it is easy to suggest bad alternatives to captchas, which is why they appear in every comment thread about captchas on Hacker News, including this one.)
I had just noticed that captchas were getting worse. I always thought sites should just make the user perform an operation. Display a hard to read but still legible "type the second letter of the third word". 'e' would be the correct response. There's got to be a reason this isn't done already, does someone know why?
Bots would spam your site once every 26 tries.
In tests on my own sites I've found that introducing reCAPTCHA during the registration process leads to a significant increase in people abandoning their registration when they fail at recognising the text the first time, without putting a significant dent in spammer registration at all. I've found it far more effective to do things like randomising form field names (instead of using names like 'username' and 'password') so the spammer has to scrape the site to figure out which fields he needs to submit for each and every account he registers, silently dumping registrations that don't use the correct field names, and then applying various heuristics to successful registrations to detect patterns common to spammers.
For instance, one particular spammer always seemed to use the same user agent string and didn't ever trigger any of the AJAX calls on the page. It was trivial to detect registrations coming from that one spammer and silently dump new accounts when he created them.
I've got several times math symbols written in captchas instead of words.. how I'm supposed to write them?
There was an interesting talk that mentioned CAPTCHA by one of its creators, Luis von Ahn, at the AAAI-12 conference on AI and robotics this past week. In ReCAPTCHA, the two-word CAPTCHA version, one of the two words is taken from a scanned book. That (unknown) word was one that failed OCR for that book. The other word is one that captcha already knows the answer to. The assumption is if you get the known captcha cor…
The assumption behind recaptcha was a novel one, but it seems pretty obvious that the OCR is really just about as good as humans anyway - the 'difficult words' that usually get served are most commonly either non-existant words (printing/writing errors) or scanning/cropping errors.
It's easy to criticize captchas. That's why there are so many articles like this, which we all knowingly nod along to as we read. It's much harder to provide productive criticism that leads to an actual improvement over the status quo. (Although it is easy to suggest bad alternatives to captchas, which is why they appear in every comment thread about captchas on Hacker News, including this one.)
I don't disagree, but what is your point? That one should never say "X is broken" without inventing a Y that is better than X?
CAPTCHA seems relatively pointless at stopping spammers since there are dozens of online services that use human labour to solve them for a dollar per thousand. In tests on my own sites I've found that introducing reCAPTCHA during the registration process leads to a significant increase in people abandoning their registration when they fail at recognising the text the first time, without putting a significant dent in…
It's easy to criticize captchas. That's why there are so many articles like this, which we all knowingly nod along to as we read. It's much harder to provide productive criticism that leads to an actual improvement over the status quo. (Although it is easy to suggest bad alternatives to captchas, which is why they appear in every comment thread about captchas on Hacker News, including this one.)
It's easy to criticize captchas. That's why there are so many articles like this, which we all knowingly nod along to as we read. It's much harder to provide productive criticism that leads to an actual improvement over the status quo. (Although it is easy to suggest bad alternatives to captchas, which is why they appear in every comment thread about captchas on Hacker News, including this one.)
I don't disagree, but what is your point? That one should never say "X is broken" without inventing a Y that is better than X?