Luis von Ahn
Born	1979 (age 32–33)[citation needed] Guatemala City, Guatemala
Residence	United States
Institutions	Carnegie Mellon University
Alma mater	Carnegie Mellon University Duke University
Doctoral advisor	Manuel Blum
Known for	CAPTCHA, reCAPTCHA, crowdsourcing pioneer
Notable awards	MacArthur Fellowship (2006), TR35 (2007)[1]

Dr. Luis von Ahn (born in 1979 in Guatemala City, Guatemala) is an entrepreneur and an associate professor in the Computer Science Department at Carnegie Mellon University.^[2] He is known as one of the pioneers of the idea of crowdsourcing. He is the founder of the company reCAPTCHA, which was sold to Google in 2009.^[3] As a professor, his research includes CAPTCHAs and human computation,^[4] and has earned him international recognition and numerous honors. He was awarded a MacArthur Fellowship (a.k.a., the "genius grant") in 2006,^[5][6] the David and Lucile Packard Foundation Fellowship in 2009, a Sloan Fellowship in 2009, and a Microsoft New Faculty Fellowship in 2007. He has also been named one of the 50 Best Brains in Science by Discover Magazine, and has made it to many recognition lists that include Popular Science Magazine's Brilliant 10, Silicon.com's 50 Most Influential People in Technology, Technology Review's TR35: Young Innovators Under 35, and FastCompany's 100 Most Innovative People in Business.

Siglo Veintiuno, a leading newspaper in Guatemala, chose him as the person of the year in 2009. In 2011, Foreign Policy Magazine in Spanish named him the most influential intellectual of Latin America and Spain.^[7]

Biography[link]

Von Ahn grew up in Guatemala City. He attended the American School of Guatemala and graduated from it in 1996. He received a B.S. in mathematics (summa cum laude) from Duke University in 2000. He obtained a Ph.D. from Carnegie Mellon University in 2005 under the supervision of professor Manuel Blum, who is well known for advising some of the most prominent researchers in the field of computer science. In 2011, he was awarded the A. Nico Habermann development chair in computer science,^[8] which is awarded every three years to a junior faculty member of unusual promise in the School of Computer Science.

Work[link]

Von Ahn's early research^[9] was in the field of cryptography. With Nicholas J. Hopper and John Langford, he was the first to provide rigorous definitions of steganography and to prove that private-key steganography is possible.

In 2000, he did early pioneering work with Manuel Blum on CAPTCHAs,^[10] computer-generated tests that humans are routinely able to pass but that computers have not yet mastered.^[11] These devices are used by web sites to prevent automated programs, or bots, from perpetrating large-scale abuse, such as automatically registering for large numbers of accounts or purchasing huge number of tickets for resale by scalpers. CAPTCHAs brought von Ahn his first widespread fame among the general public due to its coverage in The New York Times, USA Today, Discovery Channel, NOVA scienceNOW, and other mainstream outlets.

Von Ahn's Ph.D. thesis, completed in 2005, was the first publication to use the term "human computation" that he had coined for methods that combine human brainpower with computers to solve problems that neither could solve alone. Von Ahn's Ph.D. thesis is also the first work on Games With A Purpose, or GWAPs, which are games played by humans that produce useful computation as a side-effect. The most famous example is the ESP Game,^[12] an online game^[13] in which two randomly paired people are simultaneously shown the same picture, with no way to communicate. Each then lists a number of words or phrases that describe the picture within a time limit, and are rewarded with points for a match. This match turns out to be an accurate description of the picture, and can be successfully used in a database for more accurate image search technology. The ESP Game was licensed by Google in the form of the Google Image Labeler, and is used to improve the accuracy of the Google Image Search. Von Ahn's games brought him further coverage in the mainstream media. His thesis won the Best Doctoral Dissertation Award from Carnegie Mellon University's School of Computer Science.

In July 2006, von Ahn gave a tech talk at Google on "Human Computation" (i.e., crowdsourcing) that became viral and was watched by over one million viewers.^[14]

In 2007, von Ahn invented reCAPTCHA, a new form of CAPTCHA that also helps digitize books. In reCAPTCHA, the images of words displayed to the user come directly from old books that are being digitized; they are words that optical character recognition could not identify and are sent to people throughout the Web to be identified. ReCAPTCHA is currently in use by over 100,000 web sites and is transcribing over 40 million words per day.^[15]

As of 2011, von Ahn is working on Duolingo, a project that aims to coordinate millions of people to translate the Web into every major language.^[16]

Teaching[link]

Von Ahn has used a number of unusual techniques in his teaching, which have won him multiple teaching awards at Carnegie Mellon University.^[17] In the fall of 2008, he taught a new course at Carnegie Mellon entitled "Science of the Web".^[18]

See also[link]

• MacArthur Fellows Program

References[link]

External links[link]

• Luis von Blog, Luis von Ahn's weblog
• Luis von Ahn on Twitter
• Google Tech Talk on human computation by Luis von Ahn
• Google Image Labeler
• John D. and Catherine T. MacArthur Foundation
• Example of SEO Project given at CMU
• Profile: Luis von Ahn NOVA scienceNOW aired 2009-06-30
• Luis von Ahn at TED Conferences