Translator: Joseph Geni Reviewer: Morton Bast
Everyone is both a learner
and a teacher.
This is me being inspired
by my first tutor,
my mom,
and this is me teaching
Introduction to Artificial Intelligence
to 200 students
at Stanford University.
Now the students and I
enjoyed the class,
but it occurred to me
that while the subject matter
of the class is advanced
and modern,
the teaching technology isn't.
In fact, I use basically
the same technology as
this 14th-century classroom.
Note the textbook,
the sage on the stage,
and the sleeping guy
in the back. (Laughter)
Just like today.
So my co-teacher,
Sebastian Thrun, and I thought,
there must be a better way.
We challenged ourselves
to create an online class
that would be equal or better
in quality to our Stanford class,
but to bring it to anyone
in the world for free.
We announced the class on July 29th,
and within two weeks, 50,000 people
had signed up for it.
And that grew to 160,000 students
from 209 countries.
We were thrilled to have
that kind of audience,
and just a bit terrified that we
hadn't finished preparing the class yet. (Laughter)
So we got to work.
We studied what others had done,
what we could copy and what we could change.
Benjamin Bloom had showed
that one-on-one tutoring works best,
so that's what we tried to emulate,
like with me and my mom,
even though we knew
it would be one-on-thousands.
Here, an overhead video camera
is recording me as I'm talking
and drawing on a piece of paper.
A student said, "This class felt
like sitting in a bar
with a really smart friend
who's explaining something
you haven't grasped, but are about to."
And that's exactly what we were aiming for.
Now, from Khan Academy, we saw
that short 10-minute videos
worked much better than trying
to record an hour-long lecture
and put it on the small-format screen.
We decided to go even shorter
and more interactive.
Our typical video is two minutes,
sometimes shorter, never more
than six, and then we pause for
a quiz question, to make it
feel like one-on-one tutoring.
Here, I'm explaining how a computer uses
the grammar of English
to parse sentences, and here,
there's a pause and the student
has to reflect, understand what's going on
and check the right boxes
before they can continue.
Students learn best when
they're actively practicing.
We wanted to engage them, to have them grapple
with ambiguity and guide them to synthesize
the key ideas themselves.
We mostly avoid questions
like, "Here's a formula, now
tell me the value of Y
when X is equal to two."
We preferred open-ended questions.
One student wrote, "Now I'm seeing
Bayes networks and examples of
game theory everywhere I look."
And I like that kind of response.
That's just what we were going for.
We didn't want students to memorize the formulas;
we wanted to change the way
they looked at the world.
And we succeeded.
Or, I should say, the students succeeded.
And it's a little bit ironic
that we set about to disrupt traditional education,
and in doing so, we ended up
making our online class
much more like a traditional college class
than other online classes.
Most online classes, the videos are always available.
You can watch them any time you want.
But if you can do it any time,
that means you can do it tomorrow,
and if you can do it tomorrow,
well, you may not ever
get around to it. (Laughter)
So we brought back the innovation
of having due dates. (Laughter)
You could watch the videos
any time you wanted during the week,
but at the end of the week,
you had to get the homework done.
This motivated the students to keep going, and it also
meant that everybody was working
on the same thing at the same time,
so if you went into a discussion forum,
you could get an answer from a peer within minutes.
Now, I'll show you some of the forums, most of which
were self-organized by the students themselves.
From Daphne Koller and Andrew Ng, we learned
the concept of "flipping" the classroom.
Students watched the videos
on their own, and then they
come together to discuss them.
From Eric Mazur, I learned about peer instruction,
that peers can be the best teachers,
because they're the ones
that remember what it's like to not understand.
Sebastian and I have forgotten some of that.
Of course, we couldn't have
a classroom discussion with
tens of thousands of students,
so we encouraged and nurtured these online forums.
And finally, from Teach For America,
I learned that a class is not
primarily about information.
More important is motivation and determination.
It was crucial that the students see
that we're working hard for them and
they're all supporting each other.
Now, the class ran 10 weeks,
and in the end, about half of the 160,000 students watched
at least one video each week,
and over 20,000 finished all the homework,
putting in 50 to 100 hours.
They got this statement of accomplishment.
So what have we learned?
Well, we tried some old ideas
and some new and put them together,
but there are more ideas to try.
Sebastian's teaching another class now.
I'll do one in the fall.
Stanford Coursera, Udacity, MITx
and others have more classes coming.
It's a really exciting time.
But to me, the most exciting
part of it is the data that we're gathering.
We're gathering thousands
of interactions per student per class,
billions of interactions altogether,
and now we can start analyzing that,
and when we learn from that,
do experimentations,
that's when the real revolution will come.
And you'll be able to see the results from
a new generation of amazing students.
(Applause)