Feel good every time you solve a reCAPTCHA.

If you spend much time on-line, chances are, you have been required to solve distorted letter puzzles like below when you submit information.

CAPTCHA Examples

Facebook CAPTCHA

It is an Anti-Spam program called CAPTCHA. It stands for Completely Automated Public Turing Test To Tell Computers and Humans Apart. As soon as Yahoo! started using it, every other website started using and it really turns out to be extreamly effective to stoping spam.

Co-inventer Luis von Ahn says, "it is effective because only people, not computers can figure it out".

Luis von Ahn, Carnegie Mellon University

At first, he felt proud of its impact, then Luis started feeling bad because the thing was each time we type a CAPTCHA, essentially we waste 10 seconds of our time and if we multiply that by 200,000,000 we get the humanity as a whole is wasting like 500,000 hours everyday typing those annoying CAPTCHAs.

But he was also aware of another problem. Some libraries use computers and scanner to transcribe old books and news papers into digital archives. The problem is that letters often look murky. So, computers often transcribe words incorrectly. The reason the computer can not decipher many of those words is prescisly the same reason why computers can not read CAPTCHAs, is because they can not read distorted text.

But since people were already decoding distorted text, von Ahn revised CAPTCHA to use the hard to read text from old books as the puzzle. He has to make 20,000,000 words a day a digitize with the new program he calls reCAPTCHA.

reCAPTCHA

People are usually very happy about this as they say that well at least my time is not wasted any more. So feel good next time you have to solve those words problems. You might be helping to preserve a part of history.