Finally CAPTCHAs Are Useful?

[DaveSawers]

I hate CAPTCHAs. I know they're an effective way of fooling the form filling bots but they slow down surfing and are often very hard to read.

Now however, there's reCAPTCHA reCAPTCHA: Stop Spam, Read Books a service that sends out hard to read words from old books and articles that OCR has trouble with and uses the results to digitize the original work.

I think that's a brilliant idea because it serves two useful purposes in one go and with that in mind I'm less likely to complain about them. I may even use them instead of hand filtering the junk that comes from my various forms.

Anyone had any experience using them?

[lspence]

That's pretty cool. Thanks for the link. I just signed up for it, and I'm now using it to protect my email address, on my personal page. That was quick and easy.

[chiron]

Looks like a naughty sort could play hell with this "presumption of the second word" concept, but a cool idea anyway.

[jbladeus]

Good service.
That said, implementation of recaptcha is a bitch for us non-programming guys.

[deepsand]

Originally Posted by DaveSawers

Now however, there's reCAPTCHA reCAPTCHA: Stop Spam, Read Books a service that sends out hard to read words from old books and articles that OCR has trouble with and uses the results to digitize the original work.

If OCR has not already been able to digitize the words, then how can the respondent's entry be validated? Answer - it can't. And, if it could, then the pretense of ones "helping" to transcribe old books falls apart. However, the thought that they are "helping a good cause" does serve to take the edge off of some folks sense of annoyance.

Originally Posted by DaveSawers

Anyone had any experience using them?

TicketMaster switched to such. All one need do is to "guess" closely enough.

[Orion]

thanks for the link.. going to check that out myself!

[DaveSawers]

Originally Posted by deepsand

If OCR has not already been able to digitize the words, then how can the respondent's entry be validated? Answer - it can't. And, if it could, then the pretense of ones "helping" to transcribe old books falls apart.

TicketMaster switched to such. All one need do is to "guess" closely enough.

And the answer (quoting from the site) is:

"But if a computer can't read such a CAPTCHA, how does the system know the correct answer to the puzzle? Here's how: Each new word that cannot be read correctly by OCR is given to a user in conjunction with another word for which the answer is already known. The user is then asked to read both words. If they solve the one for which the answer is known, the system assumes their answer is correct for the new one. The system then gives the new image to a number of other people to determine, with higher confidence, whether the original answer was correct."

[imvain2]

I looked over their examples, these are still difficult for humans to read. Which at the end of the day is main problem with all captchas.

[Milo]

I'm using reCaptcha on one of my sites and have had no problems at all. Installation was done when I purchased a contact form mod, but have only had "real emails" getting thorugh, no spam, and no feedback about being hard to read. PM me if you want to look at the site in question (its not the one in my sig).

[kgun]

For the second time today I have to draw your attention to a short article I wrote months ago under the heading:

Advice for webmasters, especially those who want to set up a new site

on my own site.

Moderator delete my post if you think it is too much self promotion.

[deepsand]

Originally Posted by DaveSawers

And the answer (quoting from the site) is:

"But if a computer can't read such a CAPTCHA, how does the system know the correct answer to the puzzle? Here's how: Each new word that cannot be read correctly by OCR is given to a user in conjunction with another word for which the answer is already known. The user is then asked to read both words. If they solve the one for which the answer is known, the system assumes their answer is correct for the new one. The system then gives the new image to a number of other people to determine, with higher confidence, whether the original answer was correct."

Which, of course, serves to highlight the fact that the user is asked to do twice the work for the same reward.

Thank you for presenting that fact. I'd deliberately made no mention of such so as to avoid giving the appearance of merely bashing this particular implementation of CAPTCHA for no good reason.

It should also be noted that the "words" - some are not words at all, but seemingly random character strings - here presented are significantly less readable than those of predecessors, with the result that an even greater number of people are turning away from Ticketmaster (TM), and to the very people who TM seeks to displace, the independent ticket brokers.

The bottom line is that people do and will not like CAPTCHA that relies on their ability to recognize a deliberately obfuscated string of discreet symbols.

[incrediblehelp]

Have been using them fro a while and they work great.

[lspence]

Originally Posted by kgun

For the second time today I have to draw your attention to a short article I wrote months ago under the heading:

Advice for webmasters, especially those who want to set up a new site

on my own site.

I learn something new everyday, today it's OpenID. Thanks for the link, Kjell.

[edhan]

I have been using them for my blogs. Quite useful though spammers are using trackback to spam.

[deepsand]

Originally Posted by incrediblehelp

Have been using them fro a while and they work great.

Originally Posted by edhan

I have been using them for my blogs. Quite useful though spammers are using trackback to spam.

No matter how great they work, or useful they are, the fact remains that they are a royal PITA for users; and, many will not return to a site that employs them if at all possible. How many visits are lost is unmeasurable.

There are better CAPTCHA implementations available. These ask a multiple choice question, such as what day of the week is tomorrow, or what animal appears in the presented images, questions that are worded so as to be easily answered by a human, but not by a machine. The user need only click on the correct choice.