I am more than a little confident that everyone reading this blog has, very recently,  been asked to compete a CAPTCHA task … you know, that box with distorted words and numbers that you need to decipher before you can enter  website, post a comment, or purchase something online. (We even use it on LD.org!)



And it’s more than likely that you’ve grumbled about having to sidestep your online goal for a few seconds to complete this seemingly meaningless and annoying task. Well, read on and reconsider. Your typing those few symbols in the CAPTCHA box could be of tremendous value to individuals with LD, particularly those with dyslexia, as well as individuals with other disorders (i.e., AD/HD, visual impairments) for whom digitized text is a valued resource.

CAPTCHA is a program that was designed in 2000 to do just what it says: Completely Automated Public Turing test to tell Computers and Humans Apart. What makes it special  is that it can generate and grade tasks that humans can pass but current computer programs cannot. For example, you can read the distorted text in the CAPTCHA box, but computer programs cannot. The most obvious uses for this sort of program are to prevent spam messages from infiltrating blogs, to protect website registrations, make sure that online polls and surveys are not pirated and so on. But the power of this program goes way beyond online security.

Think about the enormous volume of text materials that is being scanned and digitized every day. There are multiple large scale projects underway across the globe to scan and digitize texts, books, magazines, newspapers, journals, you name it. And when these materials are photographically scanned and turned into optical character recognition (OCR) files, mistakes happen, so for example:

(see www.google.com/recaptcha/learnmore)

Hiring humans to review and edit these files would be virtually impossible, and here’s where CAPTCHA steps in. Imagine more than 200 million CAPTCHAs being solved by humans around the world every day, taking about 10 seconds of human effort distributed across millions of users. Individually, that's not a lot of time, but aggregate these little puzzles together and they amount to more than 150,000 human hours of work each day! CAPTCHA takes advantage of this by capturing information that helps create and refine digitized books! And a new program, called reCAPTCHA collects words flagged as unreadable by optical scanners as they digitize texts – collecting about 4 million responses every day from 40,000 websites, the equivalent of 1500 people working full-time and transcribing 60 words per minute!

To learn more about this very cool and helpful technology (OK, and sometimes annoying) from the person who invented it, watch this video. And if you are interested, check out a new site by the same company, duolingo.com which offers a way for you to learn languages (at no cost) while helping to translate the Web.