So, I'm from Guatemala.
This is a public service announcement,
that is where Guatemala is.
(Laughter)
Also, that is not where they keep the prisoners.
That is called Guantanamo.
(Laughter)
Not the same place.
So Guatemala's right below Mexico.
And for the Americans in the audience,
and let this sink in, because it really applies in most ways,
for the Americans in the audience,
you can think of it as Mexico's Mexico.
(Laughter)
Just like the US doesn't want illegal immigration from Mexico,
Mexico doesn't want illegal immigration from Guatemala.
It's a smaller country.
It's a poor country.
And well, what can I tell you,
it has much better Mexican food.
(Laughter)
Guatemala is a very poor country.
And a lot of people talk about education
as something that brings equality to different social classes.
But I always saw it as the opposite, as something that brings inequality.
Because what happens in practice
is that people who have a lot of money can buy themselves a really good education
and therefore continue having a lot of money.
Whereas people who don't have very much money
barely learn how to read and write
and therefore never make a lot of money.
And this is especially true in poor countries.
Now, I was fortunate that I received a rich person's education
even though I didn't grow up rich.
And it’s because I’m an only child.
And my mother, who was a single mother,
spent all of her resources on my education.
And this allowed me to come to college to the US
and eventually get a PhD in computer science.
Now because of all of this
about 10 years ago,
I decided I wanted to do something
that would give equal access to education to everyone.
Oh, by the way, this is what I want to talk to you about today,
giving equal access to education to everyone.
At the time, I was a professor of computer science
at Carnegie Mellon University,
and I decided to work on this with my PhD student, Severin.
The way my brain works,
all of education is just too general of a problem.
So I decided, let's start by teaching one thing.
And then I started thinking, OK, well, what should we teach first?
Should we teach math?
I mean, we both love math.
Me and my cofounder, we both love math.
And, you know, we didn't decide to do math.
Then we started thinking, well, maybe we should teach computer science.
But eventually, and this is maybe surprising to people in North America,
eventually, we decided that the best subject to start with
was teaching foreign languages.
And let me tell you why.
There's a number of reasons.
One of them is that there's a huge audience for it.
There’s about two billion people in the world learning a foreign language,
both in school and outside of schools.
Most of these people, by the way, are learning English.
About 80 percent of them are learning English.
In this weird map right here,
all the countries in green
are countries in which people are predominantly learning English.
And the reason for that
is because English can truly transform your life.
In most countries in the world,
knowledge of English can significantly increase your income potential.
So this is another reason why we decided to start with foreign languages.
And it's because you can directly make more money
if you learn another language, in particular English.
And see, this is pretty different than many other subjects.
For example, take math.
In the case of math,
just knowledge of math does not increase your income potential
because usually you have to learn math to then learn physics
to then become a civil engineer, that's how you make more money.
Whereas with languages, if you are a waiter and you learn English,
now you can be a waiter at a hotel and make more money.
So we decided, well, let's get started by teaching languages.
Now, we also convinced ourselves
that the only way to really reach a lot of people
was by using a mobile phone, or a smartphone in particular.
See, building schools all over the world is simply too expensive.
On the other hand,
most of the world's population already has access to a smartphone,
and the trend is that that fraction is only going to increase.
So we decided at the time
that we would make a way to learn foreign languages on a mobile phone
that was accessible to everyone.
And then we called it Duolingo.
Thank you.
(Applause)
Now in order to truly be accessible to everyone, rich and poor,
Duolingo uses a freemium model to support itself.
What that means is that you can learn as much as you want
without ever having to pay.
But if you don't pay,
you may have to see an ad at the end of a lesson.
Now, if you don't like ads,
you can also pay to subscribe to turn off the ads.
And it turns out that the vast majority of the revenue for Duolingo
comes from people who pay to subscribe to turn off the ads.
Now, who are these people who pay to subscribe to turn off the ads?
Well, they're usually well-off people in rich countries like the US and Canada.
Who are the people who don't pay to subscribe?
They usually come from poorer countries like Brazil or Vietnam or Guatemala.
So what I like about this model
is that it is a small form of wealth redistribution
because we're basically getting the rich people
to pay for the education of everyone.
So I like that.
(Applause)
So with smartphones, we can reach a lot of people
and we can even get the rich people to pay for the whole thing,
which is great.
However, if you're trying to deliver education with a smartphone,
you run into a humongous problem.
And it is that smartphones come equipped
with some of the most addictive drugs that humanity has ever engineered.
TikTok, Instagram, mobile games.
See, delivering education over a smartphone
is like hoping that people will eat their broccoli,
but right next to it, you put the most delicious dessert ever made.
(Laughter)
If you really want to deliver education to everyone,
not only do you have to make it accessible,
but also you have to make it so that people want to actually learn.
And with Duolingo, we've been able to do this.
And at the highest level, the way we've done this
is by making the broccoli taste like dessert.
I'll say it another way.
What we've done is that we've used the same psychological techniques
that apps like Instagram, TikTok or mobile games use
to keep people engaged,
but in this case, we use them to keep people engaged
but with education.
Let me give you some examples of these techniques.
One of the most powerful ones is the notion of a streak.
What a streak is, is it’s just a counter
that measures the number of days
that you've used the product consecutively.
You just take that number,
you put it very prominently in your product
and then people come back every day.
And the reason people come back every day is because, well,
if they don't come back, that number resets to zero
and people don't want to lose their streak.
It works.
Now, on the one side,
streaks have been criticized for, for example,
getting teens addicted to Snapchat.
But in the case of an educational app,
streaks get people to come back to study every day.
Now, to give you an idea of the power of streaks,
in the case of Duolingo,
we have over three million daily active users
that have a streak longer than 365.
(Applause)
That means they haven't missed a day in the last year or longer.
Now, fun fact about streaks.
What country do you think has the longest average streaks
for an educational app?
It's Japan.
Of course.
Shortest-ever streaks?
Latin America, baby.
(Laughter)
But we're fun, hey, we're fun.
(Laughter)
Another important mechanism to get people to come back to your product
are notifications.
On the one side, notifications can be really spammy and annoying,
but in the case of an educational product,
people actually want to be reminded to learn.
In the case of Duolingo, we have a very sophisticated AI system
that basically chooses when to send the notification
and also what to say in each notification
to maximize the probability that people come back.
Now, interestingly,
even after all this sophistication,
it turns out that the algorithm for choosing what time
to send you a notification is pretty simple.
Do you know what is the best time to send people a notification?
I'll tell you.
It's 24 hours after they used the product last.
There's an easy explanation.
If you were free yesterday at 3pm,
you’re probably free today at 3pm as well.
So this is what a very sophisticated millions of dollars of AI found.
(Laughter)
It's funny.
Now with notifications you shouldn't be spamming.
And we're not spamming, with Duolingo,
we actually stop sending notifications after seven days of inactivity.
So if you don't use Duolingo for seven days,
we stop sending you notifications.
Now, at some point it occurred to us,
if we're stopping to send people notifications,
we should let them know.
So we started sending this notification to people saying,
"Hey, these reminders don't seem to be working.
We'll stop sending them for now."
You know what people do when they get this notification?
They come back.
(Laughter)
Passive aggressive.
(Laughter)
Works for my mother, works for Duolingo.
(Laughter and applause)
These passive aggressive notifications
are really good at getting people to come back
back because they feel like our green owl mascot has given up on them,
so they come back.
And speaking of our green owl mascot, by the way,
because all our notifications come from our green owl mascot
and well, he's passive aggressive and also pretty pushy,
this has given rise to a lot of memes on the internet
that make fun of the great lengths that he will go through
to get you back to learn a language.
Here's one of my favorite ones.
This is it's a meme, it’s one of my favorite ones.
(Laughter)
Basically looks like you forgot your Spanish lessons.
And then there's an intruder alert,
presumably the owl broke into your house to get you to learn language.
Now, Duolingo has entered the zeitgeist.
And there's thousands of memes, there's SNL skits about it.
And it's because we've managed to get people to want to learn a language
by using the same techniques
that mobile games and social media use to get people engaged.
And this is a really important point,
let me say this.
I don't actually believe that there's a way to make an educational app
be as engaging as something like TikTok or Instagram or mobile games.
But the good news is that --
And by the way, the reason I don't believe that
is because ultimately you have to teach people something.
And it's hard to compete with, like, cats and celebrities.
But the good news is that I don't think you have to.
See, here's the thing.
When you're learning something, you get meaning out of it.
Whereas when you're scrolling for two hours on Instagram,
a lot of times afterwards, you feel like you just wasted your time.
So I think it's actually OK if your educational product
is only 80 or 90 percent as engaging as something like TikTok,
because the other 10 or 20 percent
will be provided by people's internal motivation,
though of course, not much more than that.
This is really a key point.
If we want to get people to do something meaningful,
you can use the same techniques that apps like social media use
to get people to do it.
And even if you're not as engaging as those apps are,
you can still get hundreds of millions of people to use your product.
In the case of Duolingo, for example,
there are more people learning languages on Duolingo in the United States
than there are people learning languages across all US high schools combined.
(Applause)
And this is true in most countries in the world.
My hope is that -- I know we can do this, but, you know,
my hope is that as humanity,
we can do what Duolingo has done for learning languages
but for all other subjects.
Where we can get people to learn math with mobile phones,
like millions of people to learn math with mobile phones
or physics or whatever.
I hope for a future in which screen time is not a bad thing,
in which we can deliver high-quality education to everyone, rich or poor,
using a mobile phone.
But the single most important thing that I can end this talk with,
is a reminder to please, pretty please, I beg you,
do your language lessons today.
Thank you very much.
(Laughter)
Thank you.
(Applause)
Helen Walters: Luis, thank you so much.
I wonder if you can just say a little bit more about that last point,
how do you think you can apply this type of thinking
to other subjects?
So you mentioned math, and things like that.
How do you do that?
Luis von Ahn: I think in particular,
subjects that are learned through repetition
and it turns out most things that are kind of really meaningful
are learned through thousands of repetitions.
You learn to read through repetition,
you learn elementary school math through repetition.
Most things that you can learn through repetition,
you can actually gamify and turn into something like Duolingo,
where people just do it a lot and do it fun.
It's a little harder for things like explanations.
That probably is going to require some really good videos.
Sal Khan is doing a really good job with that.
But for things that require a lot of repetition,
I think we can use the same methods.
(Applause)