You've been working for Luis von Ahn. You just didn't know it.
Von Ahn is the inventor of Captcha , the Web-security tool that requires users to enter a series of hard-to-decipher characters to access a site. After his technology caught on, he began including scanned images of text from old newspapers and books, so that as people typed in what they saw, they were unwittingly being used as digital transcribers. Google later bought the technology.
Von Ahn now has a new job for you: Eliminate the world's language barriers.
His startup Duolingo is taking the same kill-two-birds-with-one-stone approach by offering free language lessons on the Web and mobile apps. As people advance through the program, the system throws in real online news articles and other content for them to work on. So as users learn, say, Spanish, they're simultaneously translating Spanish stories on the Internet. Meanwhile, in the background, Duolingo's system itself is getting cues from users on how to become better at translating.
A big promise of the Web has been to make all of the world's information easily accessible, but foreign languages still get in the way. So even as people from around the globe increasingly jump online and contribute content to the Web, much of it remains out of reach to those who don't speak the native tongue.
"We say it's the World Wide Web, but it's quite partitioned into different languages," said von Ahn. "Everything on the Web needs to be translated."
To do that, von Ahn estimates that Duolingo will need "tens of millions" of people. So far, he's hooked about a million active users of the free software, which is available on the Web, iPhones, and starting today, Android devices . Because Duolingo relies on people instead of computers, translations can read more naturally, complete with colloquialisms, than those from automated systems.
Of course, convincing tens of millions of people to do anything -- let alone, learn a language -- is hard. Duolingo only supports six languages right now, not including any of the Asian dialects that are used by about half of the world's population. Support for Chinese languages is in the works, von Ahn said.
The lessons in Duolingo are presented in a game-like format where the player gets a set number of lives to complete a level before advancing to the next. In a study sponsored by the company, researchers from Queens College in New York and the University of South Carolina found that spending 34 hours studying with Duolingo is roughly equivalent to a semester in a college class.
Through data analysis of its users, Duolingo also has been able to refine how it teaches languages. For example, the company learned that it's more effective to expose students to adjectives before adverbs.
But even with Duolingo's gaming feel, von Ahn isn't targeting the "Angry Birds" crowd. The largest audience for language-learning tools includes those unable to buy software, such as the programs sold by Rosetta Stone, he said. The new Android app should help Duolingo better reach those people, who are more likely to have a cheap smartphone than an iPhone or even a computer, he said.
Working-class people are "learning English to get ahead in life," said von Ahn, who was born in Guatemala and emigrated to the U.S. after he finished high school. "The people who need it the most simply can't afford it."
Von Ahn, a computer-science professor at Carnegie Mellon University in Pittsburgh, has made a career out of projects designed to solve two problems at once. Typically, his software provides a benefit to the user, whose actions also contribute to a larger societal good in the background. With Captcha, companies gained more secure websites and, in the process, collectively helped make decades-old copies of the New York Times searchable on the Internet.
In 2002, he worked on a project called ESP Game. In it, two strangers are randomly matched together with no way to communicate. One by one, the pair is shown the same image, and they're each asked to enter words or phrases to describe the picture. They advance to the next stage once both have entered the same description. Google bought that one, too, and used it to improve its database of images. More than 10 million people played it, von Ahn said.
His latest two-fer, Duolingo, based in Pittsburgh and New York, could challenge both Rosetta Stone, the language-teaching-software maker, and Google, von Ahn's former employer that offers translation services as a key feature of its search engine and Android mobile operating system. Google didn't respond to a request for comment.
Rosetta Stone plans to target emerging markets by offering cheaper software, said Jonathan Mudd, a spokesman for the company. Rosetta Stone recently acquired Livemocha, a company that provides free and $10-a-month Web-education tools.
Among those who have invested a total of $18.3 million in Duolingo are New Enterprise Associates, Union Square Ventures and actor Ashton Kutcher.
"Luis is attacking a huge market," said Harry Weller, a director on Duolingo's board and general partner at NEA. "The world is globalizing, so translations are needed more than ever."