Comments on: Chaining CAPTCHAs for fun and profit? http://www.daniel-lemire.com/blog/archives/2008/01/30/chaining-captchas-for-fun-and-profit/ Daniel Lemire's blog is about life in academia, research in Computer Science, wondering how we can reconcile fast databases and algorithms with the informal and asemantic nature of the world around us. It is broadcasted from Montreal (Canada). Fri, 21 Nov 2008 21:05:49 +0000 http://wordpress.org/?v=2.6.3 By: Stefan Ciobaca http://www.daniel-lemire.com/blog/archives/2008/01/30/chaining-captchas-for-fun-and-profit/#comment-49781 Stefan Ciobaca Sat, 15 Mar 2008 01:12:44 +0000 http://www.daniel-lemire.com/blog/archives/2008/01/30/chaining-captchas-for-fun-and-profit/#comment-49781 Why do you think that the human error will be the same for the 4 CAPTCHAs? Maybe humans gets tired after filling the first one and then their performance drops. Also: why do you think the number of people who take the time to fill one CAPTCHA will be equal to the number of people willing to fill 4? I have a strong suspicion it would drop. Why do you think that the human error will be the same for the 4 CAPTCHAs? Maybe humans gets tired after filling the first one and then their performance drops.

Also: why do you think the number of people who take the time to fill one CAPTCHA will be equal to the number of people willing to fill 4? I have a strong suspicion it would drop.

]]> By: Jonathan Katz http://www.daniel-lemire.com/blog/archives/2008/01/30/chaining-captchas-for-fun-and-profit/#comment-49724 Jonathan Katz Sun, 03 Feb 2008 19:53:22 +0000 http://www.daniel-lemire.com/blog/archives/2008/01/30/chaining-captchas-for-fun-and-profit/#comment-49724 The CHS paper is the right reference...don't their results already give what you want? The CHS paper is the right reference…don’t their results already give what you want?

]]> By: ade http://www.daniel-lemire.com/blog/archives/2008/01/30/chaining-captchas-for-fun-and-profit/#comment-49720 ade Thu, 31 Jan 2008 13:53:22 +0000 http://www.daniel-lemire.com/blog/archives/2008/01/30/chaining-captchas-for-fun-and-profit/#comment-49720 Have you seen ReCaptcha: http://recaptcha.net/learnmore.html They're using 2 captchas and turning the cpu power of the 'evil machines' to their own ends. Currently that consists of digitising books from the Internet Archive. Have you seen ReCaptcha: http://recaptcha.net/learnmore.html

They’re using 2 captchas and turning the cpu power of the ‘evil machines’ to their own ends. Currently that consists of digitising books from the Internet Archive.

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