Official Duolingo Blog

Duolingo's Data-Driven Approach to Education

Thu, 31 Jan 2013 14:33:00 -0500

With the recent buzz about Duolingo and education, we thought we’d share our plan for becoming the most awesome language-learning tool in the world. Not only are we free, now and forever, but we take our product and the knowledge you gain über-seriously. So we are busting out the lab coats and nerd glasses to (1) find evidence that Duolingo actually teaches you effectively, and (2) figure out how we can use science to teach you even better. We also wanted to keep you in the loop, so we’ll be blogging about it!

A Customized Language Education

Every time you finish a Duolingo lesson, translation, test, or practice session, you provide valuable data about what you know and what you’re struggling with. Our system uses this info to plan future lessons and select translation tasks specifically for your skills and needs. Similar to how an online store uses your previous purchases to customize your shopping experience, Duolingo uses your learning history to customize your learning experience.

This kind of adaptive and net-native approach to education is pretty unique to us. In contrast, most language-learning software has a rigid, one-size-fits-all curriculum. You can get a personalized education from a small classroom teacher or private tutor, but there are many people in the world who want to learn a language and can’t afford these classes. Moreover, with a traditional “semester” course — be it in a classroom or an online MOOC — teachers can only assess what did or didn’t work once every few months; then they have to wait until the next semester to improve. At Duolingo, our language experts and engineers tweak the site literally every day to make it better for you and a million other language-learners.

Measuring What You Learn

In this post, we want to tell you how we can measure what you learn, and how we determine if our daily tweaks actually improve learning. Most of the education world measures learning with standardized tests, and there is already some evidence that Duolingo does a very good job at improving scores for the WebCAPE university placement test for Spanish. We don’t want to have you take standardized tests all the time, though. That would be slow and expensive to do for every little tweak!

It turns out that the skill points you earn from lessons, tests, and translations — combined with how often you have to “peek” at word meanings during practice sessions — provide a good prediction of what your WebCAPE score would actually be:

For the scientifically inclined, these predictions are only off by 66 points on average, and the correlation coefficient between the predictions and real scores is 0.68. For comparison, people taking the Spanish WebCAPE twice in a row yields a coefficient of 0.86, according to the official WebCAPE website. All of these results are statistically significant (p < 0.00001).

How This Helps Us Improve

When we design a new Duolingo feature to help you learn better, we first test it out with a small fraction of our users to see if these metrics (higher skill points and fewer word peeks) improve. If they do, then we can be confident that the new feature will help you score better on standardized tests, too. So if you are motivated to earn those coins, you are well on your way to mastering a new language. How cool is that?

Ciao! You may now begin learning Italian

Tue, 18 Dec 2012 13:25:15 -0500

Duo has started preparing for his trip to Rome.

Duolingo on the go. Our iPhone App is here!

Tue, 13 Nov 2012 10:59:00 -0500

The Duolingo iPhone app is now available on the app store!

Just like our website, the app is completely free, with no ads, hidden fees, or paid “premium” content. The app has all the lessons available on Duolingo, so you won’t miss out on any learning. It’s the perfect way to make your breaks and commutes more productive.

We also worked hard to make the Duolingo experience feel right at home on mobile. For example, we introduced a new type of exercise in which you form sentences by tapping on the appropriate words instead of having to type them on the small keyboard.

Android users, we have heard your cries! We have a small team, and it takes a lot of work to make the Duolingo experience excellent on each mobile platform. We are working on the Android version, but it will not be ready until next year. In the meantime, we will continue making the web version better for Android devices.

Enjoy!

Portuguese is Here!

Tue, 30 Oct 2012 14:29:00 -0400

Excited about the next World Cup in Brazil? Or maybe you just want to learn what this country has to offer besides soccer, samba and Carnival? Either way, you can now learn Brazilian Portuguese on Duolingo!

With almost 200 million people, Brazil has the sixth largest economy in the world, so this is not a language to miss.

Portuguese is still in Beta, so you may experience a few bugs, but we’ll be working as fast as we can to make it perfect.

Enjoy!

Ready, Set, Practice!

Thu, 25 Oct 2012 15:36:51 -0400

Quick! You have 7 seconds left. What does “Sie liest die Zeitung” mean?

There is a new timed mode in Practice where you have to finish before the clock runs out. You get points and extra time for every correct answer.

The timer is completely optional, but in real-world conversations you have to think quickly. We hope this type of practice makes learning more fun and helps you think on your toes. Give it a try!

A New Skill Page

Mon, 01 Oct 2012 15:18:00 -0400

Starting today we’re rolling out a new Skill Page for every learner on Duolingo. Here are some of the changes along with a quick description of our thought process.

It’s a path

Previously you had to choose between lessons and real-world translations to make progress. We’ve simplified the learning experience by giving you a clear indication of what we think is best for learning.

In the new page, you learn a skill by doing all lessons and master it by translating the real-world sentences from a set of skill-related translations. You can still master a skill by testing out of it.

Baked-in Vocabulary

Whenever you complete a lesson, you can now see a handy list of the words you’ve learned on the lower part of the skill page. If you want to practice those words, just go to your Vocabulary page and hit Practice.

Unified Skill Points

Skill points are no longer used to measure your progress in a skill. Previously you were able to earn two different kinds of points within a skill: Global skill points and skill-related points. Only skill-related points made your skill progress go up.

To simplify our currencies we now have only one type of skill point on Duolingo. You still earn them by doing lessons and translations but they are only used to measure your progress towards the next language level.

The Skill Page is a central element of your learning experience and we think the new page gives you better guidance as well as making your progress more visible.

Tenemos Dinero

Mon, 17 Sep 2012 11:00:00 -0400

Today we are very happy to announce a US$15 million investment in Duolingo led by New Enterprise Associates (NEA), with participation from our previous investor Union Square Ventures. Given the strong and growing demand for language learning and translation services, especially in developing countries, NEA’s global network and focus on education makes the firm a natural partner for us as we expand internationally.

With the investment, we are also happy to add Harry Weller from NEA to our board. Here’s what Harry had to say:

“Duolingo’s founders have fused a very ambitious mission—making the Web accessible to everyone—with an elegantly architected solution that simultaneously fuels worldwide language learning and targets a massive language translation need. We view this as an opportunity to partner with an exceptional founding team in a space we’re very excited about.”

We’ll use the funds to continue improving Duolingo and to add way more languages :)

Translation Tab Redesign!

Tue, 07 Aug 2012 09:46:00 -0400

We’re rolling out a new way to discover documents to translate. If you go to the Translations tab, you will now be able to vote on the articles you like and see the most popular ones that others have voted on. You can also browse documents based on categories such as Travel and Wikipedia.

To make this work well, we rely on people like you to identify the good stuff, so make sure you rate a lot!

New Vocabulary Section

Thu, 19 Jul 2012 14:36:46 -0400

Based on your feedback, we’ve added a page in which you can see all the words you’ve learned with Duolingo. It’s fun! You can see the size of your vocabulary and how well you know each word. You can also practice words individually and see some of our sample sentences for them.

Our goal is to make the best possible language learning site, and we think the new vocabulary section brings us one step closer to this.

100% Free Language Education, Open to the World.

Tue, 19 Jun 2012 10:36:55 -0400

Our baby was born today. Like new parents, we’re beaming with excitement to announce that Duolingo is now open to the world. We know, we’re biased, but we think she’s a beauty. Over the past six months, hundreds of thousands of beta testers have helped us refine the service. Many waited for months to get their invitations, and we want to thank them for their patience and for the more than 80,000 feedback emails they sent us. Some of them even made us blush, like this one:

“This is probably the single greatest thing currently on the internet.”

Our commitment is to continue working towards making the best language learning service out there and to always keep it 100% free.

Duolingo started as a complete long shot inside Carnegie Mellon University. We had no idea if it was going to work, but were fortunate that many others, like our investors Brad Burnham and Fred Wilson From Union Square, Ashton Kutcher from A-Grade, and Tim Ferriss, believed in our vision and took a risk with us.

So, thank you, and enjoy!

The Duolingo Team
Pittsburgh, PA

Duolingo Upload Center

Tue, 12 Jun 2012 14:55:00 -0400

You can now apply to have your content translated by Duolingo: http://duolingo.com/#/upload (until our public launch next Tuesday, you will need to have a Duolingo account to view this page).

Invite Your Friends to Duolingo!

Wed, 23 May 2012 21:25:18 -0400

As always we’ve been busy improving the Duolingo experience. There have been updates to the site almost daily, but we wanted to highlight one that hundreds of people have asked for: Starting today everybody with a Duolingo account can invite three friends to our private beta.

No need to share the same account anymore :)

Free Language Posters

Wed, 25 Apr 2012 22:59:50 -0400

A New Stream

Wed, 18 Apr 2012 17:09:29 -0400

Today we’ve started rolling out a new version of the activity stream that we hope will enhance the Duolingo experience. The biggest changes are that it now has its own tab in home, and that you can write posts on it. Because we believe everything in Duolingo should be about learning, you can only write posts on your stream in the language you’re learning. Oh, and everybody who follows you will be able to see your posts.

The goals of the new stream are to allow more interaction with other users and to provide an incentive to write in the language you’re learning. If you want to directly contact another user, just go to their profile and write on their stream.

As always, Duolingo is a work in progress, and we hope you like this new feature and help us improve it. We have several additions already planned for it (like commenting on stream events), but we wanted to let you start playing with it sooner rather than later.

Not Just Multiple Choice

Wed, 04 Apr 2012 12:33:13 -0400

What do you think is better for learning a language?

Not getting any feedback when you do something wrong;
Getting feedback only on multiple choice questions;
Being asked to produce complete sentences and getting immediate detailed feedback about them.

Our goal with Duolingo is to provide the absolute best language learning service out there (and also make it 100% free!). In this post I want to talk about something that we believe is fundamental towards this goal: students must be able to read and write complete sentences and be given immediate detailed feedback about their answers.

When we started working on Duolingo we noticed that most language learning methods outside of the classroom didn’t do this. Some never provide you with any feedback (think of books or the audio tapes from the 1980s), while other more “interactive” ones only provide you with feedback on single words or multiple choice questions. As any educator will tell you, having students read and write complete sentences by themselves, and then get detailed feedback, is significantly better for learning.

More than one way of saying the same thing

Of course, there is a reason why most interactive methods don’t do this: being able to tell you whether you formed a correct sentence is very difficult because there are many different ways of saying the same thing. For example, the Spanish sentence “Tengo una lámpara más vieja que esa en mi casa” has over 500 correct translations to English, which range from “I have a lamp that is older than that one at my house” to “At home I’ve got one lamp older than that.”

Duolingo’s Feedback System

We’ve spent the last few months working on a detailed feedback system that aims to tell you exactly what you did wrong. For example, if you enter “Das Mädchen isst ein Apfel” as a German translation for “The girl eats an apple,” Duolingo tells you, like a human teacher would, that you should have used “einen” because Apfel is a masculine noun:

And, like a teacher, Duolingo doesn’t penalize you for small typos such as when you enter “epro” instead of “pero”:

We’re very proud of this feature, and we’re improving it every day with the help of our beta testers.

We have a blog!

Fri, 30 Mar 2012 10:51:00 -0400

It’s been a few months since we started the private beta, and we couldn’t have hoped for a better response. Over 300,000 people have signed up for the waitlist, and the reactions from our users have been overwhelmingly positive — yes, we’ve read every single one of the more than 20,000 feedback emails you’ve sent (and tried to respond to most of them!). We’ve been totally consumed making the site better, but we thought it was time to take a short break to start a blog and briefly comment on our progress :)

Languages

We started Duolingo by allowing English speakers to learn Spanish and German. As of this week, Spanish speakers can now learn English, and we expect to have French in April. There have been literally thousands of requests for other languages — know that we’re working hard to add them, but it may take us a few months.

Waitlist

For those of you still waiting for an invitation, we have started inviting people faster, and we expect the waiting times to be much shorter from now on. We know the wait has been long, but we hope it’s worth it.

Thank you!

Ok, more to come later, but we want to finish this first post by thanking all of our awesome beta users for their feedback and for bearing with us when the site breaks. Our mission is very ambitious, and we won’t be able to achieve it without you.