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  5. An open letter to Duolingo


An open letter to Duolingo

I used to think that Luis von Ahn was a benevolent tech god. A clearly brilliant guy who had already made his fortune, Luis seemed to have shifted his focus to connecting the world by providing a high-quality language education to hundreds of millions…for free. I realize now that he is no different from the nineteenth-century robber barons, the Industrial Age captains of industry, the elite of Corporate America…ultimately putting profit above people. I do not fault him for that; I suppose that is just how human beings are.

Mr. von Ahn, I am truly inspired by you and am happy at your success with Duolingo blowing up and reaching the mainstream spotlight. Please, however, I beg you to remember that it’s your millions of users who have gotten you here. They liked the high quality free product you made – not what it looks like Duolingo is starting to become. Looking around at Discussion threads here and similar sites like r/duolingo, it is clear that virtually everyone hates the iOS app’s Health and Gems feature. I suffer from dyslexia and for me this update is especially irritating and anxiety-provoking; it really just sucks all the fun out of the app. My sister was getting so frustrated with the Russian course that she ended up deleting the app off her phone. I believe that I speak for many – I dare say most – when I ask that you listen to us. Your app has been a wonderful gift to the world, and many of us would be sad to lose the Duolingo that we know and love.


A concerned user, one of many

June 1, 2017



It seems to me that each change made to Duolingo over the past few months has only served to degrade the site in one way or another (deleting document tranlsation, doing away with activity stream, adding advertisements, adding languages to iOS and not the website, taking away lingots in some platforms, but not others, changing them to gems in some places and not others, at some sort of exchange rate and changing the prices of things in some platforms and not others—I don't know, it's very confusing). This health meter stuff sounds awful (and also inconsistent and confusing in its introduction and implementation (in some platforms yes, others no, some languages yes, others no).

I feel that Duolingo has lost its way, and is becoming unfocused and schizophrenic. I hope it can recover.

I honestly feel that they don't care about me and would be happy if I just get frustrated and leave.


Although this is not directed at me specifically, I work at Duolingo and am glad you are sharing your opinion. The "putting profit over people" statement is a bit unfair, though. Duolingo needs to sustain itself in order to provide a service that benefits millions of people, and also grow if we want more staff to develop more features, for more languages and platforms. And we want to do this while working hard to be the best and most efficient learning tool around. In short, we all want the same thing. If changes we experiment with are negatively impacting users' learning, we take it down. As someone who deals with the wider Duolingo community every day, I must also make a small correction:

I believe that I speak for many – I dare say most – when I ask that you listen to us. Your app has been a wonderful gift to the world, and many of us would be sad to lose the Duolingo that we know and love.

Please remember that the English language web forum (and even r/duolingo) does not necessarily reflect the opinions of all of our huge community of international learners. We have several languages and channels, and we monitor them all to be on top of what the community is feeling. We balance all that information with data and hope that the combination will allow us to offer you and the rest of the world access to free high quality language education for many years to come. Thanks for sharing your thoughts, and we hope you stick around to see some of the exciting things that we are working on.

P.S.: You can check out the Gems and Health FAQ here.


Vivisaurus, I have a great deal of respect for you and know how hard you work to help users but to claim that the millions of users using the site from other languages do not share the opinions of the English speakers is disingenuous. The other language sites are, apparently, never given the courtesy of even being informed of the changes and I personally know of French, German and Italian users among others who have had to wait for one of the English speaking users to translate the notices for them and they have then responded in exactly the same way.

Whatever the motives behind the degrading of Duo, the result for users in all languages has been a great deal of dissatisfaction and dissilussionment with the way Duo has handled things lately. Many users have left completely and others are spending less and less time here. If Duo persists in ignoring the views of its users it risks killing the goose that lays the golden egg.

We are not unreasonable, we understand that Duo needs funds to continue operating but the other changes such as loss of immersion, activity, words, exercise discussions and so on have changed the feel of the site so completely that it has lost any sense of being a mutually supportive community of language learners who helped and encouraged the new learners and become just one more do it yourself site with little or no support or motivation. It is like learning in a bubble ... the Marie Celeste of language ships.

We all appreciate how hard you work and are grateful for all you have done in the past, which is why we are trying to deflect Duo from a downward path. Sadly, following all the recent changes Duolingo has lost its soul.

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If changes we experiment with are negatively impacting users' learning, we take it down.

I am well aware of companies' secrecy and all. Yes, this is a lot to ask for, but for some 'questionable' decisions it would be nice to 'see' the data that has been statistically computed (a simple plot would suffice in many times!). Other times, the experimental design would be interesting. For experienced users, raw data could also be very interesting to run their own stats tests (didn't the Bots, "Duolingo 4.0", show a positive effect; dropped rather unexpectedly soon after being released?).

I am just writing this down, because I know that there a lot of pitoff to run into. I know that you have hired mathematic, statistic, computer science and machine learning experts, just to name a few.

Yet, the experimental design could be flawed. I have seen this before (not talking about Duolingo) but in other settings.

However, here is one mistake (not experimentally, presumably), in my opinion: release the information that the health system will be deployed on any iOS device. I, for example, have been avoiding it ever since (yes, I am perhaps an outlier). I am simply using the website (actually, on any device).



Vivisaurus, I just want you to know that I'm very thankful for Duolingo. I has given me a base in Spanish that I'm working off of to learn this beautiful language. Thanks again! :)


I'm sorry you feel that way :( I'm trying my best to keep making Duolingo better. Unfortunately from the outside it's hard to see a lot of the competing priorities we have. We get thousands of requests per day for new languages and new features. At the same time, we have to keep a system up that supports tens of millions of people actively learning languages in every single country of the world. We also spend $65,000 per day, and have to find ways to cover those costs. We actually know of a very easy way to do that: simply charge for access to all our content, like most of our competitors do. But I refuse to do that because I strongly believe in our mission to provide education even to people who don't have a bank account. So, instead of taking the easy route, we're investigating many different avenues for monetization such as a new health system and ads.

We know that some people are not fans of the new health mechanic (most of us read the subreddit, the forum and twitter daily!). Surprisingly, though, our usage metrics do not reflect this at all. On average people seem to be slightly more engaged with the health mechanic than without it. Yesterday I even asked to do an audit of the people who have most angrily complained about health in the forum or in our feedback channels and who have said they were immediately discontinuing their usage of Duolingo. Out of 25 people we looked at, all of whom threatened to leave more than two weeks ago, all but one of them were still very actively using Duolingo, some even more frequently than before.

Most people here don't know me personally, but if you did, you'd know I'm obsessed with creating a system that users love. One of the memes in the office is a sad face of me saying "daily users are down" (it's used when bad things happen). So, it is in my best interest to make sure that the health system, or any of our A/B tests, are not affecting engagement.

All of this said, we're looking A TON into how to either improve or modify the health mechanic given some of your complaints. However, these changes won't be quick to make, so I mainly ask for patience from you guys.

I personally love that we have such a passionate community, but the flip side is that we get to hear, loudly, whenever we make a change that some people don't like, and I very much take that to heart.


This is a very thoughtful and measured response. Your creation is just so great that a lot of its following is passionate, borderline zealous…and hence changes are deemed blasphemous, perhaps?

I agree with OP that the Health system is an overall net negative. I think that it’s probably reasonable for Spanish/French/Portuguese/Italian, but for more challenging languages like German and especially Russian (where you have to make heaps of mistakes before you learn anything) it feels a bit overly punitive and discouraging.

Regarding revenue, I have no problem watching ads and have even clicked on a few. If the website or iOS app had a donate button, I'd be happy to give back to a company that has helped me so much.

Anyway, those are my two cents as a longtime Duolingo user/addict. We’re with you all the way Luis; I’ve been with Duolingo since the start and look forward to seeing what the future holds.


Luis, are you considering letting users choose to write in the apps instead of choosing words? And also putting much more exercises of translation from native language to target language?


The answer to that is no, the question is has he considered implementing a setting so we could choose what kind of exercises we get including a setting for the amount of L1 -> L2 translations.


It should be obvious but when you say 24 out of the 25 complainers were actively using Duolingo, you mean on iOS, right? If those people threatened to leave because they were (understandably) disgusted by Health, I wouldn't say they necessarily backed down from their threat if they are now using a version without Health.

Secondly, does slightly better (which could as well mean people using Duo for one day more before they quit or two minutes more per day) justify going against a basic principle of teaching, not to punish students for trying and making mistakes in an area they clearly need more practice with (because they are making mistakes in that area, not some previous one)? Like people have said, if I start my day with Subjunctive, I'm not bingeing, I'm trying to understand a completely foreign concept.


It should be obvious but when you say 24 out of the 25 complainers were actively using Duolingo, you mean on iOS, right?

Yes, these were iOS users and they're still using the iOS app.

Secondly, does slightly better (which could as well mean people using Duo for one day more before they quit or two minutes more per day) justify going against a basic principle of teaching, not to punish students for trying and making mistakes in an area they clearly need more practice with (because they are making mistakes in that area, not some previous one)? Like people have said, if I start my day with Subjunctive, I'm not bingeing, I'm trying to understand a completely foreign concept.

The engagement is only slightly better (and it sustains for months), but the point is that it's not any worse, as the backlash on the forums would lead you to believe.

I understand people have many teaching philosophies, but, personally, I don't believe anything just because there is a pithy good-sounding "principle" behind it. I can easily argue against the "principle" you mention of not punishing for mistakes. For example, the most successful games of all time make people fail, quite often, and it's exactly from the mistakes that they learn better how to play these games (and get addicted to them in the process). There are hundreds of philosophies relating to language learning, many of which contradict each other, and many of which get debunked with time. Most of them are based on little to no scientific evidence. And even when there is evidence, it's usually very context-specific. I believe in our own numbers, and from what I can tell, this change doesn't hurt.


I also recommend you to look at the vote logs in this discussion if possible. Clearly the spam voting problem hasn't been solved. (Staff comments suddenly going up 5-10 points within minutes in a 2 day old discussion and more critical comments going down the same amount)


Wow! Strong words. At least they have no plans of adding the health/gem system to PC, so you can still go there.


He does have a good point. I've been getting after some of the users here for being cry babies and they have been. That being said.. Duolingo has been making some poor choices as of recently that's been hurting what made this app great. So I hope the creators take these comments seriously.


I definitely agree that a lot of people in the past have just been upset about not getting exactly what they want, without appreciating the tremendous amount of work it takes to run a tech company and figure out a working business model. However, this dramatic new change completely alters the language learning experience on mobile. To me, the best way to learn is to make countless mistakes as your brain slowly forms the right neural connections to get comfortable in a language. The Health system makes it feel like you're walking on eggshells...it kind of fills me with a small dread before I enter my answer, and in the back of my mind I need to keep track of how much Health I can spare and if I have enough gems to replenish. The supposed "binging avoidance" goal of the update sounds like a lame excuse for increased pay-to-play monetization.

Luis himself even said "negative reviews in the app store won't make us change our mind." So in his words, he clearly thinks he knows what's best for Duolingo (even if it conflicts with the opinion of his users). This is just a legitimate cause of concern for the direction the app is starting to take, that's all.

To me the app is getting more dumbed-down, tacky, and blatantly monetized with each update.


I think the health system is a good idea, but only 5 bars. Come on. There's no way people can get more than one lesson done per day. It should something like 20 bars.


I totally agree. When I started Duolingo with Spanish I became so frustrated about the three hearts on PC. I'm glad they took away the feature but many users are reliving the experience.


Well, according to the Gems and Health FAQ, you can regain health by practising what you already know instead of doing a new lesson. I think that by doing that you can reinforce what you've just done through repetition.


Which would be somewhat reasonable if you could choose what to practice instead of Duo telling you you haven't quite mastered your basics.


Yeah I'd have to agree with you there. Their algorithm that decides what you need to practice isn't perfect to say the least. Maybe someday It'll improve.


You can also access the web version from your phone by searching for Duo in your browser.


No, it forces you to go to the app now even when you search on the browser.


Yes, that option to use the web version on the telephone has indeed been removed now (=today 1 June 2017). Tried with Chrome app and Firefox app.


Oh, sorry, my mistake.


No, it's possible to access the web version from the phone.


On my telephone it absolutely has changed. Before I could e.g. choose the 'full version'. That has been removed.

I have and an icon (which is Chrome browser with URL link to duolingo.com) on my telephone for the web version (which I used many times before, so I (should) know how it has to look like) which has changed behavior and also tried by typing http://www.duolingo.com in 2 browser apps.

It might be that I am part of the so called A/B testing, that is only some users get that update.

So to double check: If you type http://www.duolingo.com in your telephone browser (I tested with Android only at this moment) and you still see the web version (e.g. including the 'Activity' app with 'new' posts like here on this forum, that has gone for me), let me know. Thanks.


I can access the full site version with discussions and all on mobile (either by url or going to Add course) but I can't do any lessons on the full site version. If I try, I'm redirected to the mobile site where I can do lessons (new and old) and use the general practice. There seems to be a scaling problem with the skill specific strengthening, it's "behind" the skills so I'm unable to click on those.

Tested on Safari, iOS


Firstly, I don't think it's helpful to your cause to insult him outright by calling him greedy.

Secondly, if they just tweaked it a little I think it would be alright. Booting people mid-lesson is absurd and just too harsh. Making mistakes is part of learning! If they used the hearts as a grading system instead, it would be a lot better IMO.

Lastly, please keep in mind the old saying, "The squeaky wheel gets the grease." We notice those making noise over the issue, but Duolingo staff has stated that the results show the health system does work. 200 people being noticed because they complain does not change the 4000 people that are quietly happy. It is impossible to judge from the forums just how well- or ill-received the change actually is.


I have just finished an exercise. At the end it always says please wait and after a few seconds the score comes up. Today I waited and waited and nothing happened. wWhen I tried to leave the site I was asked if I really wanted to leave as if I did my work would not be counted. This is very frustrating and it is the second time it has happened. I complained by email last time but never got a response. Last time \i realise that my internet connection failed just as I got to the end but this time the internet is still working. What can I do? Catriona

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