SARAH HANSEN: Well, you have a
lot of followers of your 18.06
videos.
GILBERT STRANG:
That's wonderful.
SARAH HANSEN: And I'll
read this quote to you.
"A commenter even noted
that this is not lecture,
this is art."
GILBERT STRANG: Gosh.
OK.
Well, if you're going to ask
what's my system, I have none.
I guess-- well, first
I like students.
And I want to help.
And maybe the key point
is to think with them.
Not to just say, OK, here
it is, listen, listen up.
I think through the question
all over again as they do.
And you have to give time.
You can't zip through a proof.
Because this class has to be
sort of thinking with you.
And that's-- yeah,
that's my thought.
I don't know if I achieve it,
but I think it's the goal.
SARAH HANSEN: One
of our users on OCW
noted that during
lectures you sometimes ask
rhetorical questions, or maybe
feign confusion as a way--
GILBERT STRANG: Feign confusion?
I'm confused.
SARAH HANSEN: Are you?
OK.
GILBERT STRANG: Well, no.
Well, no, it's probably true.
That's maybe part of
not rushing through it.
But getting-- so I'll pause
at the critical point, maybe.
You have to give time to see,
OK, what's the next step?
You know, mathematics
is beautifully ordered,
and sensible, and logical.
And linear algebra
is not too difficult.
But still, you can't rush.
You have to sort of see
the idea a few times.
First maybe on the
board as symbols.
But not everybody
picks up on symbols.
Then you say, what does it mean?
And then finally you
say, why is it true?
But you don't say,
"Why is it true?
Give the proof,"
the very first step.
You want to make people
think, yeah, it is true.
SARAH HANSEN: Others have noted
that you do this thing where
you display your own
thinking kind of on the spot
as you work through problems.
GILBERT STRANG: Yeah.
SARAH HANSEN: Is there ever
a risk in that for you?
GILBERT STRANG: Oh, yes.
And it happens, that
I lose the thread
or I come up to a dead
end where I don't know
what I'm supposed to do next.
But generally, especially in
18.06, The basic linear algebra
course that many
people have watched,
there I kind of get it OK.
Yeah, I've taught
it enough times
to have a good chance
of getting it right.
SARAH HANSEN: Is this a strategy
that you developed over time?
You know, lots of people
are nervous to do that,
to make themselves vulnerable
in front of a large lecture
class like that.
But you're working
problems in real time
and demonstrating what happens
when you hit a dead end.
GILBERT STRANG: Well,
that's OK, because students
are going to hit dead ends, so
it seems to me it's OK for me
to get stuck, too.
And then if they see,
oh, OK, maybe this
is the way to get
out of that corner.
Yeah.
So essentially I think the
thing is I like students.
I like math.
And putting them together is
just the best job in the world.
SARAH HANSEN: Let's talk
about humor for a second.
GILBERT STRANG: OK.
SARAH HANSEN: You
have been known
to say things like, keep things
in their Gauss-given order.
GILBERT STRANG: I see.
SARAH HANSEN: And other really
funny things that people
just love.
So what's the role of
humor in your teaching?
GILBERT STRANG:
Well, maybe it's--
which is what I'm saying
here, maybe the key point
is to make it human.
You know, you're a person,
like the student is a person.
The book isn't quite a person,
but it was written by a person.
And to see that it's just
like a natural thing to do.
Yeah.
Yeah.
Yeah.
SARAH HANSEN: So
one of our users
was thinking about how you
teach complex material, how
you convey it in ways that
are comfortable for students.
And the user was
wondering, how do
you know when to go into
detail and when not to?
GILBERT STRANG: I suppose I try
to think it through once again.
And then you sort
of automatically
see the word-- you recognize
what words you need to use,
and what the steps are.
Yeah.
If you're not
thinking it yourself,
then you're probably
going too fast
and not connecting with
the thinking of the class.
SARAH HANSEN: And
how do you connect
with the thinking of the class
when it's such a large lecture
hall?
And everyone's at a different
point in their understanding.
GILBERT STRANG:
That's probably true.
And of course, you don't
know what everybody
is thinking in that class.
But overall, if you get--
if you stay sort of conscious
of the class, conscious of where
they are, that's, I think,
the thing for any speaker,
is to be conscious
of the audience
and not just a A-B inverse.
SARAH HANSEN: What
else would you
like to add about teaching
18.06 linear algebra?
GILBERT STRANG: Well, with
18.06 of course, I'm just--
so, recently, Open
CourseWare, which I think
was just such a great idea.
Great idea for MIT.
Great idea for faculty.
So they did a count of the
number of viewers in 18.06,
and it was 10 million.
Which was like, woo.
I never expected.
But I do get nice,
really nice messages
from all over the world.
And I reply to
them far as I can.
Sometimes they'll ask what's
a good way to learn math?
I don't know if I have
an answer to that.
But anyway, I try
to be encouraging.
So yeah.
It's been wonderful.
Just having the video
lectures available
allows everybody
to be in the class.
Yeah.
So, thank you all for
joining the class.
Thank you.
