Lets teach for mastery not test scores Sal Khan
I’m here today to talk about
the two ideas that,
at least based on
my observations at Khan Academy,
are kind of the core,
or the key leverage points for learning.
And it’s the idea of mastery
and the idea of mindset.
I saw this in the early days
working with my cousins.
A lot of them were having trouble
with math at first,
because they had all of these gaps
accumulated in their learning.
And because of that, at some point
they got to an algebra class
and they might have been a little bit
shaky on some of the pre-algebra,
and because of that, they thought
they didn’t have the math gene.
Or they’d get to a calculus class,
and they’d be a little bit
shaky on the algebra.
I saw it in the early days
when I was uploading
some of those videos on YouTube,
and I realized that people
who were not my cousins were watching.
(Laughter)
And at first, those comments
were just simple thank-yous.
I thought that was a pretty big deal.
I don’t know how much time
you all spend on YouTube.
Most of the comments are not “Thank you.”
(Laughter)
They’re a little edgier than that.
But then the comments
got a little more intense,
student after student saying
that they had grown up not liking math.
It was getting difficult as they got
into more advanced math topics.
By the time they got to algebra,
they had so many gaps in their knowledge
they couldn’t engage with it.
They thought they didn’t
have the math gene.
But when they were a bit older,
they took a little agency
and decided to engage.
They found resources like Khan Academy
and they were able to fill in those gaps
and master those concepts,
and that reinforced their mindset
that it wasn’t fixed;
that they actually were capable
of learning mathematics.
And in a lot of ways, this is how
you would master a lot of things in life.
It’s the way you would
learn a martial art.
In a martial art, you would
practice the white belt skills
as long as necessary,
and only when you’ve mastered it
you would move on to become a yellow belt.
It’s the way you learn
a musical instrument:
you practice the basic piece
over and over again,
and only when you’ve mastered it,
you go on to the more advanced one.
But what we point out –
this is not the way a traditional
academic model is structured,
the type of academic model
that most of us grew up in.
In a traditional academic model,
we group students together,
usually by age,
and around middle school,
by age and perceived ability,
and we shepherd them all
together at the same pace.
And what typically happens,
let’s say we’re in a middle school
pre-algebra class,
and the current unit is on exponents,
the teacher will give
a lecture on exponents,
then we’ll go home, do some homework.
The next morning,
we’ll review the homework,
then another lecture, homework,
lecture, homework.
That will continue for about
two or three weeks,
and then we get a test.
On that test, maybe I get a 75 percent,
maybe you get a 90 percent,
maybe you get a 95 percent.
And even though the test identified
gaps in our knowledge,
I didn’t know 25 percent of the material.
Even the A student, what was
the five percent they didn’t know?
Even though we’ve identified the gaps,
the whole class will then
move on to the next subject,
probably a more advanced subject
that’s going to build on those gaps.
It might be logarithms
or negative exponents.
And that process continues,
and you immediately start to realize
how strange this is.
I didn’t know 25 percent
of the more foundational thing,
and now I’m being pushed
to the more advanced thing.
And this will continue for months, years,
all the way until at some point,
I might be in an algebra class
or trigonometry class
and I hit a wall.
And it’s not because algebra
is fundamentally difficult
or because the student isn’t bright.
It’s because I’m seeing an equation
and they’re dealing with exponents
and that 30 percent
that I didn’t know is showing up.
And then I start to disengage.
To appreciate how absurd that is,
imagine if we did other things
in our life that way.
Say, home-building.
(Laughter)
So we bring in the contractor and say,
“We were told we have
two weeks to build a foundation.
Do what you can.”
(Laughter)
So they do what they can.
Maybe it rains.
Maybe some of the supplies don’t show up.
And two weeks later,
the inspector comes, looks around,
says, “OK, the concrete
is still wet right over there,
that part’s not quite up to code …
I’ll give it an 80 percent.”
(Laughter)
You say, “Great! That’s a C.
Let’s build the first floor.”
(Laughter)
Same thing.
We have two weeks, do what you can,
inspector shows up, it’s a 75 percent.
Great, that’s a D-plus.
Second floor, third floor,
and all of a sudden,
while you’re building the third floor,
the whole structure collapses.
And if your reaction is the reaction
you typically have in education,
or that a lot of folks have,
you might say, maybe
we had a bad contractor,
or maybe we needed better inspection
or more frequent inspection.
But what was really broken
was the process.
We were artificially constraining
how long we had to something,
pretty much ensuring a variable outcome,
and we took the trouble of inspecting
and identifying those gaps,
but then we built right on top of it.
So the idea of mastery learning
is to do the exact opposite.
Instead of artificially
constraining, fixing
when and how long you work on something,
pretty much ensuring
that variable outcome,
the A, B, C, D, F –
do it the other way around.
What’s variable is when and how long
a student actually has
to work on something,
and what’s fixed is that
they actually master the material.
And it’s important to realize
that not only will this make the student
learn their exponents better,
but it’ll reinforce
the right mindset muscles.
It makes them realize that if you got
20 percent wrong on something,
it doesn’t mean that you have
a C branded in your DNA somehow.
It means that you should just
keep working on it.
You should have grit;
you should have perseverance;
you should take agency over your learning.
Now, a lot of skeptics might say,
well, hey, this is all great,
philosophically, this whole idea
of mastery-based learning
and its connection to mindset,
students taking agency
over their learning.
It makes a lot of sense,
but it seems impractical.
To actually do it, every student
would be on their own track.
It would have to be personalized,
you’d have to have private tutors
and worksheets for every student.
And these aren’t new ideas –
there were experiments
in Winnetka, Illinois, 100 years ago,
where they did mastery-based learning
and saw great results,
but they said it wouldn’t scale
because it was logistically difficult.
The teacher had to give different
worksheets to every student,
give on-demand assessments.
But now today, it’s no longer impractical.
We have the tools to do it.
Students see an explanation
at their own time and pace?
There’s on-demand video for that.
They need practice? They need feedback?
There’s adaptive exercises
readily available for students.
And when that happens,
all sorts of neat things happen.
One, the students can actually
master the concepts,
but they’re also building
their growth mindset,
they’re building grit, perseverance,
they’re taking agency over their learning.
And all sorts of beautiful things
can start to happen
in the actual classroom.
Instead of it being focused
on the lecture,
students can interact with each other.
They can get deeper mastery
over the material.
They can go into simulations,
Socratic dialogue.
To appreciate what we’re talking about
and the tragedy of lost potential here,
I’d like to give a little bit
of a thought experiment.
If we were to go 400 years
into the past to Western Europe,
which even then, was one of the more
literate parts of the planet,
you would see that about 15 percent
of the population knew how to read.
And I suspect that if you asked someone
who did know how to read,
say a member of the clergy,
“What percentage of the population
do you think is even capable of reading?”
They might say, “Well,
with a great education system,
maybe 20 or 30 percent.”
But if you fast forward to today,
we know that that prediction
would have been wildly pessimistic,
that pretty close to 100 percent
of the population is capable of reading.
But if I were to ask you
a similar question:
“What percentage of the population
do you think is capable
of truly mastering calculus,
or understanding organic chemistry,
or being able to contribute
to cancer research?”
A lot of you might say, “Well,
with a great education system,
maybe 20, 30 percent.”
But what if that estimate
is just based on your own experience
in a non-mastery framework,
your own experience with yourself
or observing your peers,
where you’re being pushed
at this set pace through classes,
accumulating all these gaps?
Even when you got that 95 percent,
what was that five percent you missed?
And it keeps accumulating –
you get to an advanced class,
all of a sudden you hit a wall and say,
“I’m not meant to be a cancer researcher;
not meant to be a physicist;
not meant to be a mathematician.”
I suspect that that actually is the case,
but if you were allowed to be operating
in a mastery framework,
if you were allowed to really
take agency over your learning,
and when you get something wrong,
embrace it – view that failure
as a moment of learning –
that number, the percent
that could really master calculus
or understand organic chemistry,
is actually a lot closer to 100 percent.
And this isn’t even just a “nice to have.”
I think it’s a social imperative.
We’re exiting what you could call
the industrial age
and we’re going into
this information revolution.
And it’s clear that some
things are happening.
In the industrial age,
society was a pyramid.
At the base of the pyramid,
you needed human labor.
In the middle of the pyramid,
you had an information processing,
a bureaucracy class,
and at the top of the pyramid,
you had your owners of capital
and your entrepreneurs
and your creative class.
But we know what’s happening already,
as we go into this information revolution.
The bottom of that pyramid,
automation, is going to take over.
Even that middle tier,
information processing,
that’s what computers are good at.
So as a society, we have a question:
All this new productivity is happening
because of this technology,
but who participates in it?
Is it just going to be that very top
of the pyramid, in which case,
what does everyone else do?
How do they operate?
Or do we do something
that’s more aspirational?
Do we actually attempt
to invert the pyramid,
where you have a large creative class,
where almost everyone
can participate as an entrepreneur,
an artist, as a researcher?
And I don’t think that this is utopian.
I really think that this
is all based on the idea
that if we let people
tap into their potential
by mastering concepts,
by being able to exercise agency
over their learning,
that they can get there.
And when you think of it
as just a citizen of the world,
it’s pretty exciting.
I mean, think about
the type of equity we can we have,
and the rate at which civilization
could even progress.
And so, I’m pretty optimistic about it.
I think it’s going to be
a pretty exciting time to be alive.
Thank you.
(Applause)