Mrs. Beth Cueni Carnegie Mellon CAPTCHA Mrs. Beth Cueni Carnegie Mellon

Luis Von Ahn Intro Video https://www.youtube.com/watch?v=-Ht4qiDRZE8

CAPTCHA Stands for Completely Automated Public Turing test to tell Computers and Humans Apart."

Who and Why Coined in 2000 Luis von Ahn (Carnegie Mellon) Manual Blum (Carnegie Mellon) Nicholas J. Hopper (Carnegie Mellon) John Langford (IBM) To stop spammers

Question posed Which is the best Computer Science Graduate School in the US?

Where are they used? To stop automated postings to blogs, forums, wikis Sorry, no example!

To purchase tickets

To create email accounts

ReCAPTCHA that uses CAPTCHA to help digitize the text of books reCAPTCHA is currently digitizing the archives of the New York Times Twenty years of The New York Times have been digitized and the project hopes to have the 110 other years done by 2010.

ReCAPTCHA 200 million CAPTCHA’s per day 10 sec of human time per CAPTCHA 400,000,000 or 6% of the world’s population has helped to digitize books

ReCAPTUCHA reCAPTCHA supplies subscribing websites with images of words that OCR – optical character recognition software has been unable to read. The subscribing websites (whose purposes are generally unrelated to the book digitization project) present these images for humans to decipher as CAPTCHA words, as part of their normal validation procedures. They then return the results to the reCAPTCHA service, which sends the results to the digitization projects. This provides about the equivalent of 160 books per day, or 12,000 man-hours per day of free labor (as of September 2008

Two words Typing 2 English words takes as long as typing 6-8 random characters One word the computer knows Second word is given to many people Chances are, if they match one word, they’ll match the other word

Reusing Wasted Cycles How people spend their time Electronic Games 9 billion human hours of Solitaire played in 2003 Building the Empire State building – 7 million human-hours Panama Canal – 20 million human hours

GWAP GWAP – Games with a purpose ESP Game 2 player online game Object of the game – type the same word for the given image Taboo words 2 ½ minutes to label 15 images

ESP Guesses change over time Partner Britney Spears Hot, crazy, rehab, shaved head Partner Love or hate their partner based on responses

Audio ESP game Tag-a-tune See responses But you may or may not be listening to the same clip

Wasted Time Survey Learning something new Learning a foreign language Why? To help translate Wikipedia to different languages MONOLINGO – release date Oct 16th