Can Duolingo Teach Foreign Students English?

News and views from academia.
July 31 2014 7:42 AM

Does Duolingo Pass the Test?

Carnegie Mellon partners with the language-learning app to make it good enough to prep students for the TOEFL.


Photo illustration by Slate. Photo by Chloe Fan via Wikimedia Commons.

This story originally appeared in Inside Higher Ed.

Carnegie Mellon University is partnering with Duolingo, one of its spinoffs, to see if a 20-minute, $20 test is sufficient to prove international students’ English proficiency. Duolingo, meanwhile, hopes its test can upend the market.

Duolingo, a crowdsourced Web translation project created by researchers in Carnegie Mellon’s computer science department, spun off from the university in November 2011 to become a venture capital-backed startup. The company now offers language learning Web and smartphone apps.


Last week, the company released Duolingo Test Center, a stand-alone app intended for language learners interested in more than deepening their vocabularies. Duolingo is breaking into what the company’s head of marketing, Gina Gotthilf, described as the “archaic” industry of language proficiency tests, starting with English.

To study in the U.S., most international students have to produce evidence that they can speak and write in English, usually by taking a standardized test. The IELTS and TOEFL, two such tests, have long dominated the landscape of English proficiency tests, but they can cost hundreds of dollars, take hours to complete, and require students to travel to approved test centers on specific dates.

Duolingo, in comparison, promises a 20-minute, $20 test that can be completed at home on a computer or smartphone—and produce equally representative results of a student or job-seeker’s English proficiency. 

“The test-taking industry—especially for language certification—is pretty much a monopoly,” Gotthilf, who also heads the company’s international development efforts, said in an interview. “It just seems really silly that people can’t get jobs or a chance to study somewhere because they can’t take these tests.”

In the absence of proctors, Duolingo requires test-takers to snap a picture of a valid photo ID, then one of themselves. Using the built-in camera on the computer or smartphone, the app then matches photos to test-takers and monitors them for suspicious behavior such as excessive background noise or glances at something outside the camera’s field of vision. The recording is later verified by a third-party proctoring service.

The test consists of four types of questions. Test-takers have to pick out English words from a lineup that in one example included “boax,” “champoo” and “dac”; listen to a sentence and transcribe it; record themselves reading; and complete fill-in-the-blank questions. The test adapts itself to the test-taker’s level of proficiency, becoming easier or more difficult in response to correct or incorrect answers.

Some of the test’s content comes from the public domain—a passage from Moby Dick appeared in one question—but the test also pulls in data from Duolingo’s learning app, which processes about one test each second, said Burr Settles, a lead scientist and software engineer with the company.

“What the machine is trying to learn here is how well you know English, and it explores the space of sophistication in the language and quickly tries to zero in on where you are,” Settles said. Twenty minutes is enough for the adaptive algorithms to build a profile of the test-taker, he said, adding that it also pushes the limit for how long someone is willing to stare at his or her smartphone.

Google is supporting the launch, which may explain why the app is only available on the Web or on Android. An iOS version—as well as French and Spanish tests—is in the works.

Back to Carnegie Mellon

Building a new language proficiency test only gets Duolingo halfway there. Unless colleges, universities, and employers in English-speaking countries accept the test, it will remain a novelty.



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