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PROFESSOR: Welcome, everybody.

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So this is the one group meeting
that we'll have with

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all you folks.

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We really appreciate your
willingness to come and help

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us teach 6-172.

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Saman will explain what the
course is all about, and then

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I will give a presentation,
a little bit, of what your

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expected responsibilities are,
and then Eric, who is one of

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our TAs, will present what the
first project that they've

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been working on is all about.

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We think we have a pretty good
acronym, OK, MIT POSSE.

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Masters in the Practice of
Software Systems Engineering,

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OK, and it is very much like a
posse, in that we're trying to

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sort of deputizing you folks to
help us deal with this mass

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of students that we deal with.

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There's no way, given the
resources that we have

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available at MIT, that we
could possibly give the

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attention to each of the
students examples of code, and

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so our strategy is to go out
and deputize some people to

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help us teach.

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As we'll discuss your
responsibility is not to do

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any grading, OK, or even any
understanding of the course

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content, OK?

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But rather to ask good questions
of the students so

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that they understand what
it's like to do software

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development, and you'll see that
most of the students are

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very immature when it comes
to coding practices.

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They have taken a minimum of
one systems course before

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this, basically.

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SAMAN AMARASINGHE: Probably two
classes where they write

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very small programs--

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PROFESSOR: Where they write a
very small programs, so they

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have no sort of sense
of writing scale.

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Moreover the class that we're
teaching because it's on the

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topic of performance
engineering, they are inclined

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to break all the rules in
order to get the best

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performance.

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And that's part of our game but
of course what we want is,

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we want the countervailing--

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you still have to make things
maintainable, you really

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should do it this way, yeah
it's fine to violate some

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abstractions here and there, but
then you should document

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that you're violating those
abstractions and so forth.

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And that's what we're counting
on you for, is to insert some

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experience and common sense.

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So, Saman, take it away.

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SAMAN AMARASINGHE: OK, good,
so to add to what Charles

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said, when I was an undergrad,
when I took something like a

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science class, or a physics
class, or engineering class,

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most of the problems had kind
of right answer and a wrong

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answer and then it's very easy
to grade those things.

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But when I took something like
an English class, all the

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papers I wrote, somebody really
went through carefully

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and graded it and gave me lot
of insightful comments so I

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can kind of develop my
own style of writing.

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And what happens in software is
the programming there's a

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style that each individual has
to develop their style, but

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they can't develop a very
haphazard style so there's a

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certain set of good styles,
certain bad styles.

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And the problem that is in a
large class we can grade for

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correctness very easily, we can
also look at the programs

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and have a very fast thing,
okay, saying, here are no

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comments, or your comment
doesn't seem to be, it's too

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verbose, or some very high level
feedback, but it's very

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hard to help somebody
build their style.

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And so what you guys are coming
into is to help us get

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these young students create
their own style of

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programming.

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The nice thing about
this class--

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and also sometimes last year the
masters found it a little

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bit hard was, we are giving
them small amount of code.

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They are doing performance
engineering on a maximum

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couple of hundred
lines of code.

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There's no very complicated
class structures or

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something like that.

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So we are not looking at the
style and software engineering

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in the macro level, how to
structure large classes but

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more at the micro level.

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In each method do they
have right style?

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Are they is it clean?

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Are they commenting
them properly, or

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can they do it better?

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So at that level at least the
building blocks that they're--

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as they go build a larger and
larger program they can

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hopefully use.

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So that's what we're looking at,
and it helps to instead of

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dumping you ten thousand lines
of code, you only get a couple

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of hundred lines of code, so you
can actually go through it

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a lot more carefully,
and help them out.

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So this is starting with a crazy
eye chart that is our

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new curriculum that we
introduced in the department.

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So what you have is some early
courses in here, these are

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basically very general
math courses, early

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courses that do--

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they probably write about ten
lines of code type thing in

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these courses, and then we feed
into these foundation

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courses and then after that
we sit at, this says 197,

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actually what should be 172.

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We sit at that level, so we are
sitting at that level, and

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then the prerequisite for people
who are coming is that

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they're taking a computer
architecture course so they

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know a little bit about
architecture.

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They have taken this
introductory software course,

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so they have written some Java
programs, and so they know a

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little bit about software
engineering from that course,

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and they have taken algorithms
course, so they understand

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algorithms somewhat, so this
is the background of the

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people are coming in.

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At the low end there might be
some people who have only

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written couple of thousand lines
of code in their lives,

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and there are other people who
are, written half probably--

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the Linux kernel.

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So there are kind of very
diversified group of people.

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But there's some people who it's
really new to them, and

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they don't even understand why
you had to do good nice

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programming, why do you have
to document these things.

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I mean, for them it's a very
new concept, because they

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haven't seen that.

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So OK, if you're writing ten
lines, OK, why do you need

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document that, I know
how to do this.

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So part of that is this is,
for a lot of them it's eye

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opening, and in last year also
we talked to students, they

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actually gained a lot from
talking to you guys.

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It's easy for us to tell them
do it, a lot of them say OK,

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just to get the grade, I will
do it, but after that I'm

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never going to do these things,
and they just go off

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in very like, mad at us for
asking them to do it, but when

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you guys say this is what
happens in industry, there's a

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lot more impact on what
they're going to do.

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And so I would go through very
fast, so we have done case

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study on Matrix Multiply show
doing how you can basically do

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things like algorithmic tricks,
architecture tricks,

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and stuff like that
get really good

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performance on Matrix Multiply.

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So we started with doing very
object oriented, immutable

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type matrices, Matrix
Multiply and then go

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down to doing blast.

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How much a performance gap
do you think that has?

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AUDIENCE: It probably depends
on how big the

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matrices are because--

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SAMAN AMARASINGHE: Yeah
it is 2k by a 2k

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matrix so it is, yeah--

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So somebody said 200x.

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AUDIENCE: 10x

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SAMAN AMARASINGHE: Yeah 10x,
so actually, in fact we've

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been-- since I started with
the immutable matrix, very

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object oriented stuff like
that, and then did all to

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optimize I could,
I got 300,000x.

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So this is kind of extreme case,
but it illustrates how

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much, kind of, performance
sometimes is hidden in these

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applications.

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And then we talk bunch about,
these are done lectures, talk

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about some very simple things
in performance engineering,

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how to optimize loops, things
like how to get the compiler

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to do certain things.

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Some basic facts, we have bunch
of rules in there that

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we went through fast.

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And we are going to do introduce
them to performance

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analysis for a lot
of these people.

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First of all, they don't even
know their code is running

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bad, because they don't know how
to look at it other than

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getting one number then.

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Even if they know that their
code is running bad, how do

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you go about figuring
out what's going on?

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They know a little bit about
GDB but they don't know

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anything about performance
analysis, so we are

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introducing them to
tools in here.

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And we are talking about C to
Machine Code, lot of them are

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Java programmers, we already
gave them a C primer, saying

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if you're Java what does C
mean, kind of a thing.

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And I actually talk about
computer architecture today

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and talk about the entire
process they're going to use.

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They're using this Nehalem
processor and all of the

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interesting things that happen
inside the processor that they

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had to be aware of.

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And the same, maybe I will talk
about the memory system

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optimization, and then Charles
is going to talk about

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algorithms and data structures
for caches in there and some

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about storage allocation.

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We'll have a bunch of lectures
on parallelism that Charles is

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going to use Cilk Language to
illustrate how to write

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parallel programs, that's
what we are going

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to use in this class.

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And then more on parallelism,
some things like data

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synchronization issues, dig deep
into other performance

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issues in parallelism
in there.

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And then since their final
project is on Ray Tracing,

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we'll introduce them to a Ray
Tracing primer, and see how

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Ray Tracing is done
and so they can go

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into their final project.

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Then I'm going to talk a little
bit about compile

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optimization, what compilers can
do for you, and how to get

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compilers to do those
things for you.

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And a little bit about
distributed systems, so how

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can you scale out
on this point?

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It's about getting a small piece
of code to run fast, now

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how do we get millions of users
go to this very large

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scale system, and get
them to work, and

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what issues are involved.

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And then we are going to also
have about three or four case

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studies sprinkled around.

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We'll get someone from
University come and talk

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specific problems, OK, look I
had this problem, and at the

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beginning it was bad.

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Here's how I went about figuring
out why and here are

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the things I tried, these are
things worked, these didn't

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work, and how we went go.

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So kind of a very hands on
case studies about doing

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performance because what these
people has to do is develop a

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00:11:21,890 --> 00:11:22,690
methodology.

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00:11:22,690 --> 00:11:25,020
Their own methodology of how
to go about solving these

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00:11:25,020 --> 00:11:27,030
problems, and then looking at
these case studies will give

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00:11:27,030 --> 00:11:30,180
them a feel how a very
experienced person will go

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00:11:30,180 --> 00:11:32,120
about looking at some
of those problems.

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So these are the kind
of lectures we

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are doing in a nutshell.

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So the projects we are doing.

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So students' mission, what
we do is we write some

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inefficient piece of code, not
that long, and we give them

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the specific, here so this is
functionally correct but it

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runs darn slow.

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And what you can say is, OK,
take advantage of right now,

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the first project is basically
looking at algorithmic and

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data structure inefficiencies.

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So OK, trying to find better
ways of doing that and change

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this program to run faster.

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So that's their thing, so they
don't have deal with thousands

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of lines of code.

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Small program, it's correct, to
run them faster, and this

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we'll also be asking them to
write tests, so you can

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actually test their
implementation, and make sure

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that implementation
are also correct.

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00:12:19,260 --> 00:12:21,560
And basically there's
no right answer.

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This drives students crazy
because they are like, "When

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am I done?" I'm like, "You're
never done until the

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deadline," because you can keep
doing more and more and

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you could keep increasing
performance in there, and of

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course if you hit very marginal
returns and at some

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point and you might decide,
OK, that's good enough.

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And also more times
the journey is as

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important as the outcome.

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So at the end of the day you
can say I got it very fast,

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but how did you get there?

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What's the process
you followed?

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Some of these programs are easy
to get there, but if you

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haven't learned that process
you can't scale it out.

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And so, a lot of times your part
is to talk to them and

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say, "What did you do?" And say,
"Okay look why did you

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skip that stage, why didn't you
profile it?" And get them

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to get do that.

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And some will say, "Yeah, I
just look at it, I realize

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what it is." Like, no just do
something there might be

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something hidden in there, so
get through the process,

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understand the process,
that's the important.

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So the way the project works is,
we give them a project, we

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start them the project, and
there might be, some projects

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have two parts in there, and
final and a project request

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design document for them to
give us, saying what they

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figure out what's bad and what
kind of optimizing they are

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thinking of doing
in this project.

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And then we have a thing
called a beta turn-in.

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They said OK look we ran this,
we got the project and turned

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the product in, an we call
it a beta, because

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I'll tell you why.

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And then what we do is, we run
everybody's project against

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everybody, basically we run
every project, and we figure

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out who got the fastest
implementation.

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And we said OK, we announced
this and said this is the

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fastest implementation, and then
we figure out how off are

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you from the fastest, and we
have a proportion of the grade

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that's basically computer
graded.

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So we figure the fastest, you'll
get 100% for something

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that on the other hand if you
are 10x slower you get 10%.

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00:14:16,940 --> 00:14:20,900
Except, the first time we tried,
the fastest was 1,000x

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better than the slowest, so
somebody got like 0.1%, that

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didn't work, so we are doing
square root of the former so

284
00:14:28,950 --> 00:14:32,390
they'll be little
bit more, in the

285
00:14:32,390 --> 00:14:34,570
somebody, got 1,000x there.

286
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So sometimes it's because
somebody just missed one

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00:14:37,570 --> 00:14:42,200
critical insight and so and also
they might not have done

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00:14:42,200 --> 00:14:44,280
the test properly and stuff
like this, so we give them

289
00:14:44,280 --> 00:14:44,810
opportunity.

290
00:14:44,810 --> 00:14:48,200
And then after this beta turn-in
you get this code, and

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00:14:48,200 --> 00:14:52,340
the TAs get this code to run and
do a very fast check over

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00:14:52,340 --> 00:14:56,560
that and that, and then they
are going to have a week to

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find a time with you, sit down
for hour or 90 minutes, and go

294
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through this code.

295
00:15:01,350 --> 00:15:04,420
And then they will get all the
feedback, the performance

296
00:15:04,420 --> 00:15:06,610
feedback, and they can talk to
people and figure out what

297
00:15:06,610 --> 00:15:09,290
they missed and they get another
chance to fix all

298
00:15:09,290 --> 00:15:11,770
those things, get the
performance up to turn in, and

299
00:15:11,770 --> 00:15:13,550
there'll be another performance
measurement, but

300
00:15:13,550 --> 00:15:16,120
now if they match up to that
point, they can get a full

301
00:15:16,120 --> 00:15:20,880
amount so of course, if people
exceed they don't get extra,

302
00:15:20,880 --> 00:15:23,600
because we want to limit the
competition, but at least you

303
00:15:23,600 --> 00:15:25,980
get a chance to kind of match
up the best code.

304
00:15:25,980 --> 00:15:30,290
So, what you have is this design
review week, that they

305
00:15:30,290 --> 00:15:34,380
get to talk to you, and get
feedback and, then after that,

306
00:15:34,380 --> 00:15:36,762
they fix everything up
and then resubmit it.

307
00:15:36,762 --> 00:15:38,960
PROFESSOR: You should mention
the beta tests.

308
00:15:38,960 --> 00:15:41,940
SAMAN AMARASINGHE: Yes, so what
also we do in this is

309
00:15:41,940 --> 00:15:44,940
we're asking them also to create
a test suite, and we

310
00:15:44,940 --> 00:15:48,050
are going to run everybody's
programs against everybody's

311
00:15:48,050 --> 00:15:53,750
test suite, and also give them
points on coverage of their

312
00:15:53,750 --> 00:15:57,910
suite, and also how well
their program does

313
00:15:57,910 --> 00:15:58,760
against everybody else.

314
00:15:58,760 --> 00:16:03,380
So if somebody finds lot of
bugs in other programs, or

315
00:16:03,380 --> 00:16:06,870
some there's a test that founds
couple of bugs that

316
00:16:06,870 --> 00:16:09,740
nobody else found we will give
a lot of points for that

317
00:16:09,740 --> 00:16:12,040
person, because that means they
went and did a really

318
00:16:12,040 --> 00:16:13,480
good job in creating
a test suite.

319
00:16:13,480 --> 00:16:16,330
So we are actually using that
to basically emphasize on

320
00:16:16,330 --> 00:16:19,290
testing and testability
issues in there.

321
00:16:19,290 --> 00:16:22,280
And then final, when you're turn
in, then the TAs will, at

322
00:16:22,280 --> 00:16:25,770
that point, will grade for
performance and also the

323
00:16:25,770 --> 00:16:26,760
coding style.

324
00:16:26,760 --> 00:16:29,680
So that time they will go to the
code and assign the grade.

325
00:16:29,680 --> 00:16:32,310
And so if the students have
listened to you, and carried

326
00:16:32,310 --> 00:16:35,100
out what you said, they should
get really good grades on that

327
00:16:35,100 --> 00:16:35,970
part, and then they had
to also provide

328
00:16:35,970 --> 00:16:38,080
a write up in that.

329
00:16:38,080 --> 00:16:42,110
So this is kind of the flow
of the projects we have.

330
00:16:42,110 --> 00:16:46,580
And the project one is a simple
algorithmic and data

331
00:16:46,580 --> 00:16:47,200
structure trick.

332
00:16:47,200 --> 00:16:52,160
So we did things like data
rotator, bit flip counter, and

333
00:16:52,160 --> 00:16:54,800
this Pentominoes Puzzle
that he's going to

334
00:16:54,800 --> 00:16:55,850
explain a little bit.

335
00:16:55,850 --> 00:16:58,720
So we give these things, that
we have a pretty inefficient

336
00:16:58,720 --> 00:17:03,300
representation, where most of
them has a much better bit

337
00:17:03,300 --> 00:17:06,400
representation, and you can do
bit tricks to basically get

338
00:17:06,400 --> 00:17:07,060
good performance.

339
00:17:07,060 --> 00:17:09,829
So these are algorithmic and
data structure representations

340
00:17:09,829 --> 00:17:11,670
that can have huge performance
gains.

341
00:17:11,670 --> 00:17:14,430
So this is the first project
and this is what next week

342
00:17:14,430 --> 00:17:16,819
you're going to get.

343
00:17:16,819 --> 00:17:20,119
So project two is more about
memory system performance,

344
00:17:20,119 --> 00:17:22,660
things like image rotator
and number sorting.

345
00:17:22,660 --> 00:17:25,359
We have two parts, the first
part is we give them these

346
00:17:25,359 --> 00:17:28,650
problems, and they're supposed
to run with different data set

347
00:17:28,650 --> 00:17:32,790
sizes, look at performance
counter results and identify

348
00:17:32,790 --> 00:17:34,810
what's going on with
these programs.

349
00:17:34,810 --> 00:17:37,830
So there's one thing that
we'll give them bunch of

350
00:17:37,830 --> 00:17:40,700
source compiled, and they have
to figure out which sort is

351
00:17:40,700 --> 00:17:45,000
which by looking at performance
counters and

352
00:17:45,000 --> 00:17:45,690
different ones.

353
00:17:45,690 --> 00:17:48,180
So you had to identify, so
basically give them idea to

354
00:17:48,180 --> 00:17:51,890
basically observe a program
behavior, and then we ask them

355
00:17:51,890 --> 00:17:53,300
to go and fix some of
the performance

356
00:17:53,300 --> 00:17:54,690
issues as a second part.

357
00:17:54,690 --> 00:17:57,690
So this is a lot about basically
getting performance

358
00:17:57,690 --> 00:18:01,090
information, understanding a lot
of hardware, what's going

359
00:18:01,090 --> 00:18:04,290
on and then going and doing
some performance fixes.

360
00:18:04,290 --> 00:18:06,850
So there'll be two parts,
to this project.

361
00:18:06,850 --> 00:18:10,090
And the project three
is implementing

362
00:18:10,090 --> 00:18:12,970
efficient storage allocator.

363
00:18:12,970 --> 00:18:15,890
Most of these students find
after they've done the Java

364
00:18:15,890 --> 00:18:18,830
and Python, they come thinking
there are these objects

365
00:18:18,830 --> 00:18:21,850
running in memory, with a thing
called pointer that

366
00:18:21,850 --> 00:18:26,360
points to, and to understand
what a pointer is

367
00:18:26,360 --> 00:18:27,580
is sometimes hard.

368
00:18:27,580 --> 00:18:30,390
And this is an interesting
example that they actually do

369
00:18:30,390 --> 00:18:32,390
a lot of pointer manipulations,
and you have to

370
00:18:32,390 --> 00:18:34,420
get a lot of those things right
and you have to have

371
00:18:34,420 --> 00:18:37,030
good discipline to do that,
as well as getting some

372
00:18:37,030 --> 00:18:41,450
performance, so this is
interesting project in there.

373
00:18:41,450 --> 00:18:44,520
Here you don't get too much of
performance variance but

374
00:18:44,520 --> 00:18:48,030
students have to think very
carefully about basically

375
00:18:48,030 --> 00:18:51,550
aliasing data structures
and stuff like that.

376
00:18:51,550 --> 00:18:54,620
So getting some of this dirty
little things you have to do,

377
00:18:54,620 --> 00:18:58,430
and learning how do it right.

378
00:18:58,430 --> 00:19:00,710
And then we go into parallel
programming.

379
00:19:00,710 --> 00:19:05,050
So first part is introducing
the concept of parallelism

380
00:19:05,050 --> 00:19:07,460
giving them some simple
programs to basically

381
00:19:07,460 --> 00:19:14,310
parallelize, and then the second
part is we give them

382
00:19:14,310 --> 00:19:17,650
insertion detection we're
inserting a bunch of lines

383
00:19:17,650 --> 00:19:22,120
into a image and then they have
to figure out when these

384
00:19:22,120 --> 00:19:27,570
lines move when they actually
intersect, and so it's not

385
00:19:27,570 --> 00:19:31,360
embracing a parallel, you
have to actually do by

386
00:19:31,360 --> 00:19:34,940
intersegmenting the data into
regions and basically figuring

387
00:19:34,940 --> 00:19:36,550
out where communication is.

388
00:19:36,550 --> 00:19:38,600
So there's a lot of issue
in there to get it done.

389
00:19:38,600 --> 00:19:41,640
It's a fairly complex program
that they have to to deal with

390
00:19:41,640 --> 00:19:45,410
and so they're going to have
to think through a lot of

391
00:19:45,410 --> 00:19:47,410
parallelism issues,
synchronization issues,

392
00:19:47,410 --> 00:19:49,450
communication issues, all
those things come

393
00:19:49,450 --> 00:19:52,650
into play in here.

394
00:19:52,650 --> 00:19:57,010
And then project 5 is just a
problem set because we want to

395
00:19:57,010 --> 00:19:59,740
get to make sure that they
understood some basic material

396
00:19:59,740 --> 00:20:01,530
we did, so you don't have
to deal with that.

397
00:20:01,530 --> 00:20:03,220
We give them, actually, a write
up they don't have to do

398
00:20:03,220 --> 00:20:07,510
any coding in there and they
turn that in as a normal

399
00:20:07,510 --> 00:20:08,780
problem set.

400
00:20:08,780 --> 00:20:13,010
And the project six also you
don't have time to critique

401
00:20:13,010 --> 00:20:16,970
that because it is delivered the
last day of class, but if

402
00:20:16,970 --> 00:20:21,280
you're interested in basically
giving them some feedback, or,

403
00:20:21,280 --> 00:20:24,110
just come in to the finals
and see how they do.

404
00:20:24,110 --> 00:20:26,720
So there what they do is, this
is a really fun project, we

405
00:20:26,720 --> 00:20:31,625
give them a very unoptimized ray
tracer, and we okay here's

406
00:20:31,625 --> 00:20:34,620
an image that it can generate.

407
00:20:34,620 --> 00:20:37,210
If you generate image that
looks the same to

408
00:20:37,210 --> 00:20:38,390
us, you'll be OK.

409
00:20:38,390 --> 00:20:40,660
So you can change the algorithms
you are doing, come

410
00:20:40,660 --> 00:20:43,070
up with other things you can
do, where you can still

411
00:20:43,070 --> 00:20:48,170
maintain the visual equivalence
and then you can

412
00:20:48,170 --> 00:20:50,650
do that, you can optimize, you
can parallelize, you can do

413
00:20:50,650 --> 00:20:54,220
anything you want and
build a ray tracer.

414
00:20:54,220 --> 00:20:58,840
So they go and then we explain
to them the basics of ray

415
00:20:58,840 --> 00:21:03,260
tracing and they do lot of cool
things and a lot of these

416
00:21:03,260 --> 00:21:05,450
kids actually really change,
think through algorithmic

417
00:21:05,450 --> 00:21:11,490
issues, even look at a lot of
graphics and find different

418
00:21:11,490 --> 00:21:14,120
ways, or better ways of doing
things, and come up with

419
00:21:14,120 --> 00:21:18,250
really cool tricks and
then do really well.

420
00:21:18,250 --> 00:21:21,300
So for that we will invite
you guys to come to the--

421
00:21:21,300 --> 00:21:25,130
then we will have basically a
bake off, everyone will come

422
00:21:25,130 --> 00:21:27,770
and figure out who has the
fastest ray tracer, and they

423
00:21:27,770 --> 00:21:30,640
have the bragging rights, as
well as the grade of having

424
00:21:30,640 --> 00:21:34,682
the fastest ray tracer, so--

425
00:21:34,682 --> 00:21:36,110
PROFESSOR: I'm going
to go through this.

426
00:21:36,110 --> 00:21:37,180
SAMAN AMARASINGHE: Okay, you
go through-- we have the

427
00:21:37,180 --> 00:21:38,260
schedule here.

428
00:21:38,260 --> 00:21:43,740
So the most programs are done in
C, and very little C++, not

429
00:21:43,740 --> 00:21:47,190
very complex C++ classes,
or anything like that.

430
00:21:47,190 --> 00:21:50,990
We want them to be very
close to the metal.

431
00:21:50,990 --> 00:21:54,180
They have been trained in a lot
of abstract programming in

432
00:21:54,180 --> 00:21:56,370
Java, Python and stuff like
that, now they're going to get

433
00:21:56,370 --> 00:21:59,440
to the metal, and understand
things like pointers, malloc

434
00:21:59,440 --> 00:22:02,540
and free, native data types
and stuff like that.

435
00:22:05,740 --> 00:22:09,410
We're not dealing with things
like dealing in garbage

436
00:22:09,410 --> 00:22:12,660
collection and bound checks, and
all the other things, so

437
00:22:12,660 --> 00:22:15,350
they're really seeing what's
going close to the metal, and

438
00:22:15,350 --> 00:22:17,130
sometimes we are even
encouraging to look at at a

439
00:22:17,130 --> 00:22:19,065
little bit of assembly work,
that's not really required.

440
00:22:21,570 --> 00:22:23,710
AUDIENCE: Have these students
had exposure to any kind of

441
00:22:23,710 --> 00:22:25,510
assembly language programing?

442
00:22:25,510 --> 00:22:29,260
SAMAN AMARASINGHE: In 004, they
are using some assembly

443
00:22:29,260 --> 00:22:32,220
programming for in the
architecture class, but I

444
00:22:32,220 --> 00:22:36,750
think it's a very simple, I
think RISC machine inspection

445
00:22:36,750 --> 00:22:38,000
they're doing.

446
00:22:40,370 --> 00:22:46,570
And then we will have our course
website as you go about

447
00:22:46,570 --> 00:22:49,820
you can look at what the course
is doing and also if

448
00:22:49,820 --> 00:22:54,700
you change this F10 to a F09 you
will see last year's code.

449
00:22:54,700 --> 00:22:58,530
So you can actually even see
into the future what we have

450
00:22:58,530 --> 00:22:58,830
been doing.

451
00:22:58,830 --> 00:23:01,720
So if you want to kind of
preface from the front.

452
00:23:01,720 --> 00:23:05,017
AUDIENCE: I took a look at this
website and found that

453
00:23:05,017 --> 00:23:08,740
most of it was unavailable
because of--

454
00:23:08,740 --> 00:23:10,390
SAMAN AMARASINGHE: We should
have Word readable we need to

455
00:23:10,390 --> 00:23:12,510
make it if it's not
Word readable--

456
00:23:12,510 --> 00:23:15,250
AUDIENCE: It says it's
Word readable.

457
00:23:15,250 --> 00:23:15,660
To us.

458
00:23:15,660 --> 00:23:17,680
GUEST SPEAKER: Some of it is a
lot of it was not I've said

459
00:23:17,680 --> 00:23:20,040
you need to, I mean it's
all available for-

460
00:23:20,040 --> 00:23:20,340
AUDIENCE: Certificate?

461
00:23:20,340 --> 00:23:23,350
SAMAN AMARASINGHE: We will check
that, because all this

462
00:23:23,350 --> 00:23:25,080
things that we have set up
in the background to get

463
00:23:25,080 --> 00:23:27,140
everything Word-- we want to
make everything Word readable,

464
00:23:27,140 --> 00:23:28,845
so we'll make sure
that happens.

465
00:23:28,845 --> 00:23:35,530
So, OK, so that's all I have
about the class and one thing

466
00:23:35,530 --> 00:23:38,920
interesting more so this
projects, the best to worst

467
00:23:38,920 --> 00:23:41,230
can sometimes be 1,000x
difference.

468
00:23:41,230 --> 00:23:43,900
So what that means, even for the
people who are struggling,

469
00:23:43,900 --> 00:23:45,840
they can get something
out of the class.

470
00:23:45,840 --> 00:23:48,870
But unlike other classes where
you just read the limit and

471
00:23:48,870 --> 00:23:51,450
then you're bored, you can
really keep pushing the limit,

472
00:23:51,450 --> 00:23:53,400
especially things like the final
product, the people who

473
00:23:53,400 --> 00:23:56,280
did well really pushed the
limits, they could have done

474
00:23:56,280 --> 00:23:58,450
that for a graphics
class type thing.

475
00:23:58,450 --> 00:24:01,420
I mean they pushed algorithms
changes, did amazing

476
00:24:01,420 --> 00:24:04,200
parallelization techniques, data
partitioning, everything.

477
00:24:04,200 --> 00:24:06,590
And where some people just kind
of stayed within that and

478
00:24:06,590 --> 00:24:10,430
did some small parallelization
got some like low hanging

479
00:24:10,430 --> 00:24:11,680
fruit in there.

480
00:24:13,660 --> 00:24:15,630
I mean what we're trying to do
is, computer science these

481
00:24:15,630 --> 00:24:18,310
days, we get some students, as
I said, their first time

482
00:24:18,310 --> 00:24:20,650
they're coding anything more
than ten lines and other

483
00:24:20,650 --> 00:24:27,130
people who are already a
submitter for open source

484
00:24:27,130 --> 00:24:29,020
projects, who have written
millions of lines of code, we

485
00:24:29,020 --> 00:24:30,100
have these two.

486
00:24:30,100 --> 00:24:32,700
And these codes, I think we
are trying to cater to at

487
00:24:32,700 --> 00:24:36,770
every level, and keep everybody
basically very

488
00:24:36,770 --> 00:24:38,680
motivated, and excited
to be in there.

489
00:24:38,680 --> 00:24:41,540
And I think the last year it
was a pretty good success.

490
00:24:41,540 --> 00:24:46,790
And they really enjoy meeting
masters last year, and after

491
00:24:46,790 --> 00:24:48,760
we go to discussion we can talk
about that a little bit.

492
00:24:48,760 --> 00:24:52,010
PROFESSOR: So we have two
websites, as Saman mentioned

493
00:24:52,010 --> 00:24:55,570
before, so here they are, and
then here's the schedule.

494
00:24:55,570 --> 00:25:00,510
So we'll run through this, in
more detail for what is

495
00:25:00,510 --> 00:25:04,040
expected of you, in a moment,
but basically there's four

496
00:25:04,040 --> 00:25:06,880
projects that's sort of are
organized along here.

497
00:25:06,880 --> 00:25:08,660
Oops, that typo didn't
get fixed.

498
00:25:08,660 --> 00:25:16,060
That's should be November 19
obviously there, instead of

499
00:25:16,060 --> 00:25:17,450
October 19 if you
want to correct

500
00:25:17,450 --> 00:25:20,540
that on your calendars.

501
00:25:20,540 --> 00:25:25,700
OK, so in general it begins with
an information session

502
00:25:25,700 --> 00:25:28,270
which you're allowed to attend
in person but most people just

503
00:25:28,270 --> 00:25:30,700
dial in, it's more convenient.

504
00:25:30,700 --> 00:25:36,870
Then we will provide you with
the beta code submitted by

505
00:25:36,870 --> 00:25:39,910
your four students and then
you'll have two meetings that

506
00:25:39,910 --> 00:25:44,880
typically are 60 to 90 minutes
with each of your two pairs.

507
00:25:44,880 --> 00:25:50,815
OK, so let's go through
how this is working.

508
00:26:00,080 --> 00:26:05,440
So the first thing is just to
make sure you folks recognize

509
00:26:05,440 --> 00:26:06,650
that you're making
a commitment.

510
00:26:06,650 --> 00:26:12,490
It's very difficult for us, and
it's even more difficult

511
00:26:12,490 --> 00:26:16,570
for the students, to cope with
something that happens

512
00:26:16,570 --> 00:26:18,150
mid-term, OK?

513
00:26:18,150 --> 00:26:24,540
Where suddenly their master
disappeared, or whatever, so

514
00:26:24,540 --> 00:26:28,460
we're very big on
anti-flakiness, if you will.

515
00:26:28,460 --> 00:26:31,240
And so if you believe that
there's going to be a problem

516
00:26:31,240 --> 00:26:34,650
please let us know as much
in advance as you can.

517
00:26:34,650 --> 00:26:37,540
Sometimes things are
unavoidable, they come up, we

518
00:26:37,540 --> 00:26:39,990
don't fault you for that
or anything, OK?

519
00:26:39,990 --> 00:26:42,580
Just let us know, we'll try to
deal with the situation.

520
00:26:42,580 --> 00:26:45,510
But for the most part we're
really asking you to make a

521
00:26:45,510 --> 00:26:51,290
strong commitment to the
class, and so if your

522
00:26:51,290 --> 00:26:56,510
situation is such that you're
unsure it's best to talk with

523
00:26:56,510 --> 00:27:03,060
us or politely decline to
participate, rather than

524
00:27:03,060 --> 00:27:05,650
putting on the rosy glasses,
say, "Oh yeah I think I can do

525
00:27:05,650 --> 00:27:08,680
this, even though I know that
I've got a major deadline that

526
00:27:08,680 --> 00:27:11,440
conflicts with one of these
projects," or whatever.

527
00:27:11,440 --> 00:27:12,640
It's just really difficult
on the

528
00:27:12,640 --> 00:27:16,030
students when things change.

529
00:27:16,030 --> 00:27:20,290
They are sort of going I don't
know if you remember what it's

530
00:27:20,290 --> 00:27:23,230
like being in school as an
undergraduate, but pretty much

531
00:27:23,230 --> 00:27:26,750
the students go sort of hand
to mouth, in terms of like,

532
00:27:26,750 --> 00:27:29,300
they look and they say, OK I got
this deadline this week I

533
00:27:29,300 --> 00:27:31,150
better work on that one.

534
00:27:31,150 --> 00:27:33,800
They don't really look ahead and
so forth, and so it's up

535
00:27:33,800 --> 00:27:37,730
to us, to some extent, to
recognize that they're in that

536
00:27:37,730 --> 00:27:41,010
mode and that we need
to do things to make

537
00:27:41,010 --> 00:27:42,210
that easy for them.

538
00:27:42,210 --> 00:27:47,110
When they get sick or something
mid-term it can

539
00:27:47,110 --> 00:27:50,410
really throw a student way off
for the term, and so certainly

540
00:27:50,410 --> 00:27:58,100
when something happens to the
staff, that sort of, at that

541
00:27:58,100 --> 00:28:06,435
caliber, can really knock them
off their trajectory.

542
00:28:09,140 --> 00:28:13,260
The design and code reviews
should normally be held at

543
00:28:13,260 --> 00:28:18,385
MIT, and the students will
have some locations.

544
00:28:22,510 --> 00:28:26,660
If you are within walking
distance to campus however,

545
00:28:26,660 --> 00:28:29,750
you may suggest an alternative
place to meet, such as at your

546
00:28:29,750 --> 00:28:32,620
own workplace, if that's more
convenient for you, OK?

547
00:28:32,620 --> 00:28:36,210
But if a student balks at
doing that you shouldn't

548
00:28:36,210 --> 00:28:39,890
pressure them to accept.

549
00:28:39,890 --> 00:28:43,650
The content of the off campus
meetings should be

550
00:28:43,650 --> 00:28:47,250
professional, it's strictly
the review process, no lab

551
00:28:47,250 --> 00:28:53,680
tours, no free lunches, or
dinners, or what have you, OK?

552
00:28:53,680 --> 00:28:56,860
And we'll talk a little bit
more about that later.

553
00:28:56,860 --> 00:28:59,240
But the main thing about them is
that they can be scheduled

554
00:28:59,240 --> 00:29:03,440
in the evening or you know
whatever time you and your two

555
00:29:03,440 --> 00:29:06,680
students find convenient
to get together, OK?

556
00:29:06,680 --> 00:29:11,280
There's no limits as to
when you know what

557
00:29:11,280 --> 00:29:11,990
time those can be.

558
00:29:11,990 --> 00:29:15,940
They can be on the weekend they
can be, whatever you can

559
00:29:15,940 --> 00:29:19,030
work out, very flexible.

560
00:29:19,030 --> 00:29:22,150
So here's the basic guidelines,
each master is

561
00:29:22,150 --> 00:29:23,950
responsible for reviewing
the code

562
00:29:23,950 --> 00:29:25,370
produced by four students.

563
00:29:28,420 --> 00:29:31,940
The students typically will work
in teams of two or three

564
00:29:31,940 --> 00:29:34,150
for the projects, OK?

565
00:29:34,150 --> 00:29:38,590
So what you will have is your
four students will be

566
00:29:38,590 --> 00:29:43,380
organized into two review groups
of two students each,

567
00:29:43,380 --> 00:29:46,860
but none of the students will
be on the same project.

568
00:29:46,860 --> 00:29:49,690
The reason for that is that we
want to make sure that every

569
00:29:49,690 --> 00:29:53,860
student who goes to represent
their project can represent

570
00:29:53,860 --> 00:29:56,790
the whole project.

571
00:29:56,790 --> 00:30:00,010
So they're responsible for
the whole project.

572
00:30:00,010 --> 00:30:03,010
They don't have a buddy there
on the same team, who can

573
00:30:03,010 --> 00:30:06,180
cover for them when you're
asking them questions about

574
00:30:06,180 --> 00:30:06,970
their project.

575
00:30:06,970 --> 00:30:14,000
You ask them questions they've
got to be able to answer about

576
00:30:14,000 --> 00:30:16,950
the whole thing, even
if they didn't code

577
00:30:16,950 --> 00:30:17,810
every piece of that.

578
00:30:17,810 --> 00:30:19,830
We're encouraging them generally
to do things like

579
00:30:19,830 --> 00:30:24,120
pair programming, so they
really should understand

580
00:30:24,120 --> 00:30:30,500
what's going on throughout.

581
00:30:30,500 --> 00:30:33,390
The reason for having two
groups, rather than meeting

582
00:30:33,390 --> 00:30:37,060
them individually, it turns out
there's actually some good

583
00:30:37,060 --> 00:30:41,040
knowledge of one of them sort of
being able to see what the

584
00:30:41,040 --> 00:30:42,830
other teams are doing.

585
00:30:42,830 --> 00:30:45,480
So generally they're not
allowed to share their

586
00:30:45,480 --> 00:30:48,510
solutions, et cetera, with
other teams, but in this

587
00:30:48,510 --> 00:30:50,400
meeting that's OK.

588
00:30:50,400 --> 00:30:53,190
The ideas and so forth can come
but they shouldn't be

589
00:30:53,190 --> 00:30:55,540
making copies for each
other of the code

590
00:30:55,540 --> 00:30:56,920
of the other group.

591
00:30:56,920 --> 00:30:59,730
But they can say, oh is that
what the other team did, And

592
00:30:59,730 --> 00:31:03,710
so forth, and there can be
some learning for them to

593
00:31:03,710 --> 00:31:04,925
submit the final project.

594
00:31:04,925 --> 00:31:07,650
SAMAN AMARASINGHE: Also last
year, lot of masters very

595
00:31:07,650 --> 00:31:09,980
successfully used the other team
members to kind critique

596
00:31:09,980 --> 00:31:11,370
each other.

597
00:31:11,370 --> 00:31:14,820
So showing something do you
understand this, and then they

598
00:31:14,820 --> 00:31:17,140
can look at it and say, "Yeah,
I can see what's going on,

599
00:31:17,140 --> 00:31:20,890
that's very useful," also when
we go to masters we can talk

600
00:31:20,890 --> 00:31:22,420
about of that type of thing.

601
00:31:22,420 --> 00:31:24,550
PROFESSOR: Also things
like documentation.

602
00:31:24,550 --> 00:31:28,260
You can look at the code there
and ask the other one, "Do you

603
00:31:28,260 --> 00:31:31,180
understand what that
documentation

604
00:31:31,180 --> 00:31:32,040
says?" And so forth.

605
00:31:32,040 --> 00:31:34,820
It turns out it's actually
easier than that, because

606
00:31:34,820 --> 00:31:38,130
usually if the documentation
is inadequate, the student

607
00:31:38,130 --> 00:31:39,790
himself has trouble remembering

608
00:31:39,790 --> 00:31:40,690
what they did, right?

609
00:31:40,690 --> 00:31:45,430
I mean you know how this
works with code, so.

610
00:31:45,430 --> 00:31:49,120
So consequently you're
responsible for generally for

611
00:31:49,120 --> 00:31:52,760
two review meetings for each
of the four projects.

612
00:31:52,760 --> 00:31:55,970
Now as it turns out we'll assign
things, we're going to

613
00:31:55,970 --> 00:31:58,680
have things like students
dropping the class, and so

614
00:31:58,680 --> 00:32:02,150
there will be some minor
reshuffling as we go on.

615
00:32:02,150 --> 00:32:05,900
Some of you may end up with only
one team of two students.

616
00:32:05,900 --> 00:32:08,900
Some of you may find that you're
reconstituting it.

617
00:32:08,900 --> 00:32:11,950
In some cases if we end up--

618
00:32:11,950 --> 00:32:16,430
we may ask somebody, "Can you
cover an extra team this time

619
00:32:16,430 --> 00:32:18,000
because somebody is going
to be out of town?" Or

620
00:32:18,000 --> 00:32:18,830
something like that.

621
00:32:18,830 --> 00:32:21,270
So there may be some variations
on this, but this

622
00:32:21,270 --> 00:32:23,600
is basically how things go.

623
00:32:26,200 --> 00:32:29,280
Now, one thing you should
understand is that you are not

624
00:32:29,280 --> 00:32:32,780
going to grade the students.

625
00:32:32,780 --> 00:32:41,410
So, one of the things I learned
long ago was that when

626
00:32:41,410 --> 00:32:44,490
you grade somebody they behave
differently than if you don't.

627
00:32:47,030 --> 00:32:51,030
So you're not grading them that
has a plus and a minus.

628
00:32:51,030 --> 00:32:55,610
The plus is that then this is
really pure feedback for them.

629
00:32:55,610 --> 00:32:58,870
This is to help them, they know
that you're supposed to

630
00:32:58,870 --> 00:32:59,360
have read it.

631
00:32:59,360 --> 00:33:03,000
The downside is some students
will say, "Eh, then I don't

632
00:33:03,000 --> 00:33:06,970
need to listen, because nobody's
holding a stick over

633
00:33:06,970 --> 00:33:12,860
my head." But the reason
we do that is twofold.

634
00:33:12,860 --> 00:33:18,580
One is because we think that the
quality of interaction is

635
00:33:18,580 --> 00:33:23,200
better, and the second reason
is because you're not

636
00:33:23,200 --> 00:33:24,805
empowered by MIT
to give grades.

637
00:33:27,830 --> 00:33:30,440
So you won't be grading them.

638
00:33:30,440 --> 00:33:32,600
You're also not responsible
for the technical

639
00:33:32,600 --> 00:33:34,430
content of the class.

640
00:33:34,430 --> 00:33:36,490
We're going to be teaching
stuff, hopefully which is

641
00:33:36,490 --> 00:33:41,040
sufficiently new, some of it,
that some of you may not know

642
00:33:41,040 --> 00:33:43,400
all of what we're teaching with
respect to parallelism,

643
00:33:43,400 --> 00:33:43,960
and so forth.

644
00:33:43,960 --> 00:33:49,590
Some of you may that's great,
but that's not the role.

645
00:33:49,590 --> 00:33:51,850
We will take responsibility
for teaching the

646
00:33:51,850 --> 00:33:53,410
content of the class.

647
00:33:53,410 --> 00:33:57,240
What we're really after here
is for you to listen as an

648
00:33:57,240 --> 00:34:02,320
experienced program developer,
and provide feedback to the

649
00:34:02,320 --> 00:34:06,640
students about software
engineering.

650
00:34:06,640 --> 00:34:10,040
In other words explained to
them what's going on. "Why

651
00:34:10,040 --> 00:34:12,219
didn't you write that in
your documentation?

652
00:34:12,219 --> 00:34:14,350
How come all your variables
have only one letter?

653
00:34:17,870 --> 00:34:20,600
Why is this stuff wrapping
around three

654
00:34:20,600 --> 00:34:22,300
lines before you--

655
00:34:22,300 --> 00:34:25,580
why no white space?"
This kind of stuff.

656
00:34:25,580 --> 00:34:30,830
So, remember they're very smart
students, but they're

657
00:34:30,830 --> 00:34:32,909
also very immature
many of them.

658
00:34:32,909 --> 00:34:37,690
Some of them you'll discover
are like way mature, but

659
00:34:37,690 --> 00:34:39,969
there's going to be some of them
that are just absolutely

660
00:34:39,969 --> 00:34:42,500
this is new to them, and
what they need is some

661
00:34:42,500 --> 00:34:45,550
encouragement and some
suggestions as to what they

662
00:34:45,550 --> 00:34:48,739
can do to improve the quality
of their code.

663
00:34:48,739 --> 00:34:53,499
And since we're not in a
position to review it, why

664
00:34:53,499 --> 00:34:57,790
we're deputizing you as members
of the MIT POSSE, is

665
00:34:57,790 --> 00:35:02,940
to deputize you to help them
produce better quality code,

666
00:35:02,940 --> 00:35:05,500
which is not something that's
easy for us either to give

667
00:35:05,500 --> 00:35:07,660
feedback on, or to grade.

668
00:35:07,660 --> 00:35:10,330
So hopefully when we are grading
them in the end on

669
00:35:10,330 --> 00:35:13,900
their final submission and the
quality of things, it reflects

670
00:35:13,900 --> 00:35:17,630
that they've learned something
from you folks about

671
00:35:17,630 --> 00:35:18,940
producing good code.

672
00:35:23,290 --> 00:35:28,820
Also you want to be careful,
this is one of the bugs I have

673
00:35:28,820 --> 00:35:31,950
when I interact with the
students is, I tend to do most

674
00:35:31,950 --> 00:35:35,970
of the talking if I don't
check myself.

675
00:35:35,970 --> 00:35:39,860
And one of the really good
things is to have a guideline

676
00:35:39,860 --> 00:35:44,510
that they I don't know how many
of you have teenage kids,

677
00:35:44,510 --> 00:35:53,240
and if you lecture them how
quickly they learn right?

678
00:35:53,240 --> 00:35:54,840
No, they don't.

679
00:35:54,840 --> 00:35:58,650
So the goal here is to
help them learn.

680
00:35:58,650 --> 00:36:01,860
And so lecturing usually
doesn't work.

681
00:36:01,860 --> 00:36:03,850
What works generally is getting

682
00:36:03,850 --> 00:36:05,690
them to do the talking.

683
00:36:05,690 --> 00:36:08,110
And then it's great
to pepper your

684
00:36:08,110 --> 00:36:11,470
interactions with anecdotes.

685
00:36:11,470 --> 00:36:14,530
I work with one person who did
this, or early in my career I

686
00:36:14,530 --> 00:36:18,070
did this and here's how
it blew up in my face,

687
00:36:18,070 --> 00:36:18,900
that kind of thing.

688
00:36:18,900 --> 00:36:23,370
Excellent to have anecdotes that
you can give with real

689
00:36:23,370 --> 00:36:25,390
world experience.

690
00:36:25,390 --> 00:36:30,320
Why you might think it's like
this, but in fact, if you do

691
00:36:30,320 --> 00:36:34,330
it that way you're headed
down a very bad path.

692
00:36:34,330 --> 00:36:35,660
Let me tell you story
about that.

693
00:36:35,660 --> 00:36:36,780
That's fine, OK.

694
00:36:36,780 --> 00:36:38,780
SAMAN AMARASINGHE: Or if you
find a very stubborn person

695
00:36:38,780 --> 00:36:41,040
saying, "If you do that
I won't hire you."

696
00:36:41,040 --> 00:36:43,460
PROFESSOR: That counts too.

697
00:36:43,460 --> 00:36:48,320
You would never get a job here
if you coded like that.

698
00:36:48,320 --> 00:36:51,170
And in fact that's actually
what Saman says, that's

699
00:36:51,170 --> 00:36:54,080
actually one of the big benefits
of having folks from

700
00:36:54,080 --> 00:36:57,860
industry providing that
feedback, because we can say

701
00:36:57,860 --> 00:37:03,430
that, if you do it like that you
wouldn't be hired by XYZ

702
00:37:03,430 --> 00:37:04,640
corporation.

703
00:37:04,640 --> 00:37:08,330
You can say that, but if you
say, I wouldn't hire you, if

704
00:37:08,330 --> 00:37:13,930
you did that, that has
a, it's like, oh!

705
00:37:13,930 --> 00:37:16,250
It has a big impact, whereas
when we do it it's

706
00:37:16,250 --> 00:37:17,790
like eh, you know.

707
00:37:17,790 --> 00:37:20,120
It's like what do they know?

708
00:37:23,630 --> 00:37:27,130
So the guideline is make them
do a lot of the talking, so

709
00:37:27,130 --> 00:37:29,970
that they're trying to explain
and you teach them a little

710
00:37:29,970 --> 00:37:31,820
bit what a design and
code review is.

711
00:37:31,820 --> 00:37:34,310
Now, in fact what your
review is, is both

712
00:37:34,310 --> 00:37:36,112
design and code review.

713
00:37:36,112 --> 00:37:38,725
SAMAN AMARASINGHE: To add to
that, what we have told them

714
00:37:38,725 --> 00:37:42,320
is to prepare for what a filing
statement type thing,

715
00:37:42,320 --> 00:37:45,540
to walk through and explain
what they did to you guys.

716
00:37:45,540 --> 00:37:48,140
So they will come with some
preparations stuff that they

717
00:37:48,140 --> 00:37:52,210
can do that, let them, both of
them kind of do that, and then

718
00:37:52,210 --> 00:37:56,510
start them off the
instructive part.

719
00:37:56,510 --> 00:37:57,760
PROFESSOR: And maybe
they'll do that.

720
00:38:00,820 --> 00:38:03,170
But that's the goal is, you
should say, "Look, when you

721
00:38:03,170 --> 00:38:07,090
come you should prepare
something that brings me up to

722
00:38:07,090 --> 00:38:09,080
speed," and teach them a
little bit about what's

723
00:38:09,080 --> 00:38:12,720
expected of them when
you have a design or

724
00:38:12,720 --> 00:38:15,840
code review in industry.

725
00:38:15,840 --> 00:38:18,020
So for each of the projects, as
we mentioned, there will be

726
00:38:18,020 --> 00:38:21,690
a short information session,
typically by dialing

727
00:38:21,690 --> 00:38:23,580
conferencing, except
for this one, which

728
00:38:23,580 --> 00:38:24,840
we'll do in a minute.

729
00:38:24,840 --> 00:38:28,860
After the students have
submitted their beta releases

730
00:38:28,860 --> 00:38:32,670
we will get the code to you.

731
00:38:32,670 --> 00:38:35,030
Last year we had the students
responsible for getting the

732
00:38:35,030 --> 00:38:40,980
code to the MIT POSSE, and that
was basically a nightmare

733
00:38:40,980 --> 00:38:43,270
for everybody involved.

734
00:38:43,270 --> 00:38:47,970
So this time we will make sure
that we get you their code,

735
00:38:47,970 --> 00:38:51,580
and I hope that way the
unreliability--

736
00:38:51,580 --> 00:38:54,020
I don't know if you remember
but like, these are mostly

737
00:38:54,020 --> 00:38:57,100
like juniors and seniors, and
when you're juniors and

738
00:38:57,100 --> 00:39:00,530
seniors you're not 100% reliable
in everything you do

739
00:39:00,530 --> 00:39:04,990
and your word is your bond is
not necessarily, oh I forgot

740
00:39:04,990 --> 00:39:07,260
that my word is my bond,
kind of thing, right?

741
00:39:12,610 --> 00:39:16,400
So by us getting it to you,
we'll remove one layer

742
00:39:16,400 --> 00:39:20,270
hopefully of flakiness.

743
00:39:20,270 --> 00:39:22,540
Next what you'll do is, you'll
coordinate to meet with a

744
00:39:22,540 --> 00:39:26,190
mutually agreeable time, and
then after the review you're

745
00:39:26,190 --> 00:39:28,430
going to provide us with a
little bit of feed back, it

746
00:39:28,430 --> 00:39:33,560
doesn't have to be long, just a
short email, not as a grade

747
00:39:33,560 --> 00:39:37,760
or evaluation, but to help us
understand where the student's

748
00:39:37,760 --> 00:39:39,630
are doing well, and what
they're missing.

749
00:39:39,630 --> 00:39:43,090
So what we may need to stress
in class and so forth.

750
00:39:43,090 --> 00:39:45,340
And then, of course, after
the review, they have the

751
00:39:45,340 --> 00:39:50,320
opportunity to make changes to
their code before they submit

752
00:39:50,320 --> 00:39:52,100
their final revision.

753
00:39:52,100 --> 00:39:53,920
Now, that's a little bit
different from industry where

754
00:39:53,920 --> 00:39:57,025
you would go through typically
some kind of feature freeze,

755
00:39:57,025 --> 00:39:59,340
and code freeze, and so forth.

756
00:39:59,340 --> 00:40:04,070
Our beta is beta sort of in
name, but not necessarily in

757
00:40:04,070 --> 00:40:07,190
all aspects, in that they can
actually completely rewrite

758
00:40:07,190 --> 00:40:12,196
their code between the beta
and the final version.

759
00:40:12,196 --> 00:40:15,240
SAMAN AMARASINGHE: So in your
feedback you can also tell a

760
00:40:15,240 --> 00:40:17,410
little bit about in your
interactions what worked and

761
00:40:17,410 --> 00:40:18,040
what didn't.

762
00:40:18,040 --> 00:40:20,510
This is the first time, as far
as we know anybody's doing

763
00:40:20,510 --> 00:40:23,580
this kind of a thing anywhere.

764
00:40:23,580 --> 00:40:25,790
We are also developing
a process so

765
00:40:25,790 --> 00:40:27,340
good practice is very--

766
00:40:27,340 --> 00:40:30,020
PROFESSOR: And since your email
will go to MIT POSSE and

767
00:40:30,020 --> 00:40:35,690
everybody will read it, what
hopefully you can do is, some

768
00:40:35,690 --> 00:40:38,390
of the practices that you find
useful, I tried this at work,

769
00:40:38,390 --> 00:40:40,100
I tried this, it didn't work.

770
00:40:40,100 --> 00:40:43,360
That starts to get spread out
among you and is becomes very

771
00:40:43,360 --> 00:40:47,360
helpful for each other to say,
"Oh, well that was an

772
00:40:47,360 --> 00:40:50,660
interesting idea let me try
that." And so we hopefully

773
00:40:50,660 --> 00:40:53,933
we'll be able then to start
compiling some best practices.

774
00:40:53,933 --> 00:40:56,520
AUDIENCE: Will we be identifying
students by name

775
00:40:56,520 --> 00:40:57,888
in those broadcasting minutes?

776
00:40:57,888 --> 00:41:01,940
PROFESSOR: Yes, yes, in fact
here's the thing is, what

777
00:41:01,940 --> 00:41:04,860
you're going to do is give,
well it one, names the

778
00:41:04,860 --> 00:41:07,860
students who attended, and that
helps us keep track of

779
00:41:07,860 --> 00:41:11,270
who's actually going to
these and who isn't.

780
00:41:11,270 --> 00:41:14,330
The strengths and weaknesses in
the student presentations.

781
00:41:14,330 --> 00:41:16,360
Some suggestions for improving
the assignment.

782
00:41:16,360 --> 00:41:19,110
That's suggestions for us to
improve the assignment for

783
00:41:19,110 --> 00:41:23,690
them, and any other comments.

784
00:41:23,690 --> 00:41:26,400
So we got some really good
feedback last year that, "Hey

785
00:41:26,400 --> 00:41:31,310
the code you're handing out as
the initial code that was

786
00:41:31,310 --> 00:41:35,940
really sloppily documented."
Last year we were much more

787
00:41:35,940 --> 00:41:38,010
behind the eight-ball in terms
of trying to do this.

788
00:41:38,010 --> 00:41:40,990
This time we've had more time,
and in particular we also have

789
00:41:40,990 --> 00:41:43,790
some really outstanding TAs
who've worked very hard on the

790
00:41:43,790 --> 00:41:45,290
software engineering
of the project.

791
00:41:45,290 --> 00:41:47,730
So I think that we'll be better
in that regard, this

792
00:41:47,730 --> 00:41:49,242
year, than we were last year.

793
00:41:49,242 --> 00:41:50,540
AUDIENCE: I just
had a question

794
00:41:50,540 --> 00:41:52,210
PROFESSOR: Yeah, sure.

795
00:41:52,210 --> 00:41:54,880
AUDIENCE: You mentioned that
they're going to give to you

796
00:41:54,880 --> 00:41:56,190
and you're going to
pass the code out.

797
00:41:56,190 --> 00:41:56,495
PROFESSOR: Yes.

798
00:41:56,495 --> 00:41:59,246
AUDIENCE: Do you mean just the
code or are you thinking

799
00:41:59,246 --> 00:42:02,226
structured more as a design
review, they really will be

800
00:42:02,226 --> 00:42:05,022
talking about, a
review package.

801
00:42:05,022 --> 00:42:07,260
It would be the code plus I
don't know whether you're

802
00:42:07,260 --> 00:42:12,490
doing documentation generation
or any sort of an intro or

803
00:42:12,490 --> 00:42:12,990
front matter?

804
00:42:12,990 --> 00:42:15,440
PROFESSOR: Yeah, so the
question is whether in

805
00:42:15,440 --> 00:42:17,770
addition to the code there
should there's going to be any

806
00:42:17,770 --> 00:42:21,190
other documentation, or
package, or whatever.

807
00:42:21,190 --> 00:42:24,110
In fact, most of the final
documentation is going to be

808
00:42:24,110 --> 00:42:28,350
for the final project and not
for the beta, and so they

809
00:42:28,350 --> 00:42:31,270
should have things well
documented within the code,

810
00:42:31,270 --> 00:42:34,090
for example about what their
strategies are, and how they

811
00:42:34,090 --> 00:42:38,420
work, and so forth, but there
won't generally be a write up.

812
00:42:38,420 --> 00:42:43,240
They should be providing you at
your meeting with a brief

813
00:42:43,240 --> 00:42:46,030
outline of what's going on, and
you can ask them after the

814
00:42:46,030 --> 00:42:49,170
first meeting for any other
thing that you think would be

815
00:42:49,170 --> 00:42:53,300
helpful to them and to you in
making the design meeting more

816
00:42:53,300 --> 00:42:54,960
productive.

817
00:42:54,960 --> 00:42:57,260
One of the things always in
these things is how much do

818
00:42:57,260 --> 00:43:04,600
you require out of the students
and at which time.

819
00:43:04,600 --> 00:43:09,110
They have in this project, we're
on a relentless series

820
00:43:09,110 --> 00:43:10,520
of deadlines for them.

821
00:43:10,520 --> 00:43:13,850
And so we've tried to do as
much as we can while being

822
00:43:13,850 --> 00:43:17,520
still relatively minimalistic
in asking for too

823
00:43:17,520 --> 00:43:19,220
much stuff too early.

824
00:43:19,220 --> 00:43:22,020
And so it would be great if they
had a complete package of

825
00:43:22,020 --> 00:43:25,180
here's what's going on, the
fact is that they were up

826
00:43:25,180 --> 00:43:27,930
really late the night before
trying to get this stuff done,

827
00:43:27,930 --> 00:43:32,400
they've also had to submit beta
tests and so we decided

828
00:43:32,400 --> 00:43:35,310
that the final write up of how
their project worked, et

829
00:43:35,310 --> 00:43:38,670
cetera, we would save for the
final, and it won't be

830
00:43:38,670 --> 00:43:43,680
something, in English written
like that will only be in the

831
00:43:43,680 --> 00:43:47,970
code, it won't be as
a separate package.

832
00:43:47,970 --> 00:43:49,220
AUDIENCE: Right.

833
00:43:51,450 --> 00:43:54,260
PROFESSOR: Any other questions
about that?

834
00:43:54,260 --> 00:43:59,245
OK, so one final word,
relationships with students.

835
00:44:03,480 --> 00:44:07,590
So one of the things that MIT
has, and many other places

836
00:44:07,590 --> 00:44:09,140
have, I'm sure that you're
aware, that if you're in a

837
00:44:09,140 --> 00:44:11,940
power position with somebody,
and this in particular applies

838
00:44:11,940 --> 00:44:16,000
at MIT with students, you must
ensure that all your

839
00:44:16,000 --> 00:44:19,560
relationships are strictly
educational.

840
00:44:19,560 --> 00:44:26,540
And what that means is like
a, no romance, OK, duh.

841
00:44:26,540 --> 00:44:30,295
But it also means in this
context, no recruiting, hints

842
00:44:30,295 --> 00:44:34,010
at job opportunities, offers
of summer internships, lab

843
00:44:34,010 --> 00:44:37,540
tours, et cetera, free dinners,
and so forth.

844
00:44:37,540 --> 00:44:40,420
Your job has to be completely
educational.

845
00:44:40,420 --> 00:44:47,310
However when the term is over
you're welcome to continue

846
00:44:47,310 --> 00:44:51,720
your friendship in a non-power
relationship.

847
00:44:51,720 --> 00:44:55,810
There's no longer a power
relationship you're welcome to

848
00:44:55,810 --> 00:44:58,790
start a romance with one of the
students if you will, but

849
00:44:58,790 --> 00:45:03,450
in particular, allowed to seduce
them to come to your

850
00:45:03,450 --> 00:45:10,320
company as a summer intern,
or a job or what have you.

851
00:45:10,320 --> 00:45:16,360
So you're welcome to do that but
not during the term, those

852
00:45:16,360 --> 00:45:18,830
sorts of things are absolutely
off bounds.

853
00:45:18,830 --> 00:45:21,890
Now the students themselves may
say, "Hey do you guys have

854
00:45:21,890 --> 00:45:24,890
summer internships, and so
forth?" And it's up to you

855
00:45:24,890 --> 00:45:32,110
folks to draw the line and say
something like, "Yes, we do,

856
00:45:32,110 --> 00:45:36,110
but if you're interested in
that, we can talk about that

857
00:45:36,110 --> 00:45:39,060
after the term is over,"
for example.

858
00:45:39,060 --> 00:45:43,310
So, put them off in some way,
and return the conversation to

859
00:45:43,310 --> 00:45:45,830
the educational mission
for the term.

860
00:45:45,830 --> 00:45:46,566
Yeah?

861
00:45:46,566 --> 00:45:50,454
AUDIENCE: So what if the
students do a good job?

862
00:45:55,320 --> 00:45:58,340
PROFESSOR: Yes, but then you
run the risk of it being

863
00:45:58,340 --> 00:46:04,300
interpreted as a quid pro quo
for employment, which is

864
00:46:04,300 --> 00:46:10,820
exactly the thing that we're
trying to steer away from.

865
00:46:10,820 --> 00:46:13,950
They're smart MIT students, I
think they'll figure out that

866
00:46:13,950 --> 00:46:16,850
if they're interested in a
summer internship they should

867
00:46:16,850 --> 00:46:18,020
be impressing their mentor.

868
00:46:18,020 --> 00:46:22,065
Not all of them figure
this out, by the way.

869
00:46:22,065 --> 00:46:23,518
AUDIENCE: So just to clarify.

870
00:46:23,518 --> 00:46:26,871
Just to clarify, it's okay to
say, "If you write your code

871
00:46:26,871 --> 00:46:29,745
this way, I won't hire you."
But it's not OK to say, "I

872
00:46:29,745 --> 00:46:33,580
wouldn't hire you." I just
want to clarify.

873
00:46:33,580 --> 00:46:35,350
PROFESSOR: You'd say I wouldn't
hire you, OK, my

874
00:46:35,350 --> 00:46:37,240
company would not hire
somebody who wrote

875
00:46:37,240 --> 00:46:38,290
their code like this.

876
00:46:38,290 --> 00:46:39,220
You could say that.

877
00:46:39,220 --> 00:46:41,240
AUDIENCE: But it's not okay to
say my company looks for

878
00:46:41,240 --> 00:46:44,920
people who would write
code this way?

879
00:46:44,920 --> 00:46:47,370
PROFESSOR: No, I think
that would be OK too.

880
00:46:47,370 --> 00:46:52,010
No, the issue is whether you
personalize it, right?

881
00:46:52,010 --> 00:46:56,190
If you're interested in a summer
job, I can get you a

882
00:46:56,190 --> 00:47:00,490
summer job, all you have to do
is, dadadadadadadaaa, and now

883
00:47:00,490 --> 00:47:03,470
they feel like there's another
master to serve.

884
00:47:03,470 --> 00:47:07,110
So what we want to avoid is
having them feel like there's

885
00:47:07,110 --> 00:47:10,550
another obligation on top
of the obligation

886
00:47:10,550 --> 00:47:12,020
they have to the class.

887
00:47:12,020 --> 00:47:16,120
They should not feel that in
some ways they're obliged to

888
00:47:16,120 --> 00:47:20,080
do something for you in order,
for example, to get a job.

889
00:47:20,080 --> 00:47:20,840
SAMAN AMARASINGHE: Or
get a good grade.

890
00:47:20,840 --> 00:47:22,900
PROFESSOR: Or get a
good grade, or--

891
00:47:22,900 --> 00:47:25,562
SAMAN AMARASINGHE: If I say no
to the summer job they're

892
00:47:25,562 --> 00:47:28,708
going to badmouth me and I will
fail this class or get a

893
00:47:28,708 --> 00:47:29,676
bad grade, and then.

894
00:47:29,676 --> 00:47:33,420
So, that put them in a binding
situation that they won't work

895
00:47:33,420 --> 00:47:34,955
for the class, but they'll
feel obliged

896
00:47:34,955 --> 00:47:35,900
to something else.

897
00:47:35,900 --> 00:47:39,780
PROFESSOR: You're in a power
situation, and you're in a

898
00:47:39,780 --> 00:47:43,250
situation where you must not let
them have any sense that

899
00:47:43,250 --> 00:47:46,560
there's any power relationship
there, if you

900
00:47:46,560 --> 00:47:47,450
will, in other words--

901
00:47:47,450 --> 00:47:49,390
AUDIENCE: We shouldn't try to
extort meals from them.

902
00:47:49,390 --> 00:47:52,300
PROFESSOR: For example.

903
00:47:52,300 --> 00:47:53,755
Exactly, exactly.

904
00:47:59,960 --> 00:48:02,890
Also if you feel anything
awkward is developing, let

905
00:48:02,890 --> 00:48:06,340
Saman, or me, this is something
for which the staff

906
00:48:06,340 --> 00:48:11,330
only email is better than
probably the MIT POSSE one.

907
00:48:11,330 --> 00:48:12,910
SAMAN AMARASINGHE: Or
even to us directly.

908
00:48:12,910 --> 00:48:15,690
PROFESSOR: Or even to us
directly, although I actually

909
00:48:15,690 --> 00:48:18,600
think it better to go
via the staff only.

910
00:48:18,600 --> 00:48:20,700
It really is much better to go
get via staff only, because

911
00:48:20,700 --> 00:48:23,830
the TAs need to know what's
going on with all the students

912
00:48:23,830 --> 00:48:25,180
in class as well.

913
00:48:25,180 --> 00:48:26,365
Question back here.

914
00:48:26,365 --> 00:48:28,457
AUDIENCE: Two logistical
questions but I don't want to

915
00:48:28,457 --> 00:48:29,620
interrupt you before
you finish.

916
00:48:29,620 --> 00:48:30,550
PROFESSOR: No, that's fine.

917
00:48:30,550 --> 00:48:33,130
AUDIENCE: Okay, it's not clear
to me do we meet with the same

918
00:48:33,130 --> 00:48:35,080
four students throughout
the term?

919
00:48:35,080 --> 00:48:36,320
PROFESSOR: If possible
we will do that.

920
00:48:36,320 --> 00:48:40,210
Because otherwise what happens
is, they hear it from one and

921
00:48:40,210 --> 00:48:42,000
then they go to another.

922
00:48:42,000 --> 00:48:45,150
So this way there's some amount
of continuity, but that

923
00:48:45,150 --> 00:48:48,200
won't happen perfectly because
students will drop and we'll

924
00:48:48,200 --> 00:48:50,890
have to reconstitute
groups and things.

925
00:48:50,890 --> 00:48:53,365
GUEST SPEAKER: The winners get
David and the losers get me.

926
00:48:53,365 --> 00:48:53,860
That's OK.

927
00:48:53,860 --> 00:48:55,850
I just wanted to be clear.

928
00:48:55,850 --> 00:49:00,156
Also you e-mail the code
to us before we do

929
00:49:00,156 --> 00:49:01,120
the sit down session?

930
00:49:01,120 --> 00:49:01,602
PROFESSOR: Yes.

931
00:49:01,602 --> 00:49:03,530
GUEST SPEAKER: Are we expected
to review it by ourselves

932
00:49:03,530 --> 00:49:04,494
beforehand?

933
00:49:04,494 --> 00:49:07,386
PROFESSOR: I think it helps
to take a look at it, yes.

934
00:49:07,386 --> 00:49:09,314
GUEST SPEAKER: As opposed
to walk in cold

935
00:49:09,314 --> 00:49:10,290
and doing just that.

936
00:49:10,290 --> 00:49:12,790
PROFESSOR: Yeah, yes, that's
right, I mean I think you do a

937
00:49:12,790 --> 00:49:16,280
better job if you have looked at
the code beforehand to see,

938
00:49:16,280 --> 00:49:19,550
oh my goodness this is,
and take a few notes.

939
00:49:22,330 --> 00:49:25,380
But for this we're relying on
you to use your best judgment

940
00:49:25,380 --> 00:49:26,600
for what's the best
way of giving

941
00:49:26,600 --> 00:49:27,630
feedback to the students.

942
00:49:27,630 --> 00:49:30,400
But I think generally the reason
we email it to you in

943
00:49:30,400 --> 00:49:34,900
advance is specifically so you
have a chance to look it over.

944
00:49:34,900 --> 00:49:39,210
Once again we're not so
concerned about whether the

945
00:49:39,210 --> 00:49:43,290
content of what they're learning
in it as much as--

946
00:49:43,290 --> 00:49:46,860
you look at it, it will take you
two seconds as soon as you

947
00:49:46,860 --> 00:49:49,630
see one piece of undergraduate
code, it'll take you two

948
00:49:49,630 --> 00:49:54,660
seconds to say, I don't care
what this thing does this

949
00:49:54,660 --> 00:50:00,050
student needs to learn X.
I mean you will see.

950
00:50:00,050 --> 00:50:02,400
Is that the feedback, from
people who took this--

951
00:50:02,400 --> 00:50:04,990
AUDIENCE: You'll know
it when you see it.

952
00:50:04,990 --> 00:50:06,750
PROFESSOR: Any other comments
from people

953
00:50:06,750 --> 00:50:08,260
from last year what--

954
00:50:08,260 --> 00:50:10,950
AUDIENCE: Yeah, a
couple comments.

955
00:50:10,950 --> 00:50:17,360
One very minor sort of
procedural things.

956
00:50:17,360 --> 00:50:20,650
Personally, I found it a lot
more useful to me to show up

957
00:50:20,650 --> 00:50:23,218
in person for the information
sessions than do it by

958
00:50:23,218 --> 00:50:26,440
conference call, if for no other
reason then a lot of

959
00:50:26,440 --> 00:50:29,526
people who called in had issues
with voice quality.

960
00:50:29,526 --> 00:50:31,960
You know, just getting
a good quality voice

961
00:50:31,960 --> 00:50:33,210
signal over the phone.

962
00:50:35,250 --> 00:50:38,570
Also I found it very helpful
to have each student review

963
00:50:38,570 --> 00:50:39,280
the other one's code.

964
00:50:39,280 --> 00:50:42,289
So I would just do that to start
with, just hand it to

965
00:50:42,289 --> 00:50:44,500
each other and here,
what do you think?

966
00:50:44,500 --> 00:50:48,485
That also gives them some
experience of actually doing a

967
00:50:48,485 --> 00:50:51,630
review, as well as being
the person who's

968
00:50:51,630 --> 00:50:54,620
work is being reviewed.

969
00:50:54,620 --> 00:50:58,340
PROFESSOR: That's a great
technique just because one of

970
00:50:58,340 --> 00:51:00,530
the things that you want them
to do is empathize with the

971
00:51:00,530 --> 00:51:05,260
person who's going to read the
code, and so, by putting them

972
00:51:05,260 --> 00:51:07,350
in the situation where they have
to read somebody else's

973
00:51:07,350 --> 00:51:13,440
code they very quickly learn
oh, this is, my goodness

974
00:51:13,440 --> 00:51:16,700
that's exactly what I did to
the other one, so that is a

975
00:51:16,700 --> 00:51:17,950
great technique.

976
00:51:20,990 --> 00:51:22,458
AUDIENCE: The reference
implementations are we going

977
00:51:22,458 --> 00:51:23,700
to get those--

978
00:51:23,700 --> 00:51:24,220
PROFESSOR: Yes.

979
00:51:24,220 --> 00:51:24,980
AUDIENCE: Soon?

980
00:51:24,980 --> 00:51:25,280
Early?

981
00:51:25,280 --> 00:51:27,620
PROFESSOR: Yes, those generally
we will be able to

982
00:51:27,620 --> 00:51:32,460
give you the reference
implementations at the

983
00:51:32,460 --> 00:51:34,720
information session.

984
00:51:34,720 --> 00:51:36,730
Or actually, we should probably
get it to them before

985
00:51:36,730 --> 00:51:37,650
the information session.

986
00:51:37,650 --> 00:51:38,860
AUDIENCE: I would suggest
before the--

987
00:51:38,860 --> 00:51:40,670
PROFESSOR: Yeah, let's get those
make sure we get those

988
00:51:40,670 --> 00:51:42,890
to you before the information
session.

989
00:51:42,890 --> 00:51:44,850
We'll get you a reference
implementation at least a few

990
00:51:44,850 --> 00:51:45,680
days in advance.

991
00:51:45,680 --> 00:51:49,570
AUDIENCE: OK, also something
that was a recurring issue

992
00:51:49,570 --> 00:51:51,890
last year regarding the
reference supplementations

993
00:51:51,890 --> 00:51:53,140
which was the...

994
00:51:55,510 --> 00:51:56,840
there was some issues with
some of the reference

995
00:51:56,840 --> 00:51:57,135
implementation--

996
00:51:57,135 --> 00:51:57,430
[INTERPOSING VOICES]

997
00:51:57,430 --> 00:51:59,300
SAMAN AMARASINGHE: --software
engineering.

998
00:51:59,300 --> 00:52:03,290
AUDIENCE: In particular things
like functions that should

999
00:52:03,290 --> 00:52:07,156
have been local to a file they
were not declared static or,

1000
00:52:07,156 --> 00:52:12,060
that kind of thing, or macros
that should have been used or

1001
00:52:12,060 --> 00:52:13,974
that were used and shouldn't
have been.

1002
00:52:17,240 --> 00:52:20,060
PROFESSOR: Last year we were
running with a much larger

1003
00:52:20,060 --> 00:52:23,600
class than we expected, with no
infrastructure to speak of,

1004
00:52:23,600 --> 00:52:30,000
and we had two TAs who were flat
out, and so we definitely

1005
00:52:30,000 --> 00:52:30,440
cut corners.

1006
00:52:30,440 --> 00:52:33,570
This year the department has
been good to us, we have four

1007
00:52:33,570 --> 00:52:39,480
TAs, and so I think that the
quality is going to be higher.

1008
00:52:39,480 --> 00:52:48,230
That doesn't mean that the TAs
are seasoned 20 years of

1009
00:52:48,230 --> 00:52:51,510
software development experience
or more, either.

1010
00:52:51,510 --> 00:52:58,990
So they have some things to
learn too, but already based

1011
00:52:58,990 --> 00:53:01,940
on the first project we're
ahead of the game.

1012
00:53:01,940 --> 00:53:05,060
AUDIENCE: OK, also if from time
to time one of us wants

1013
00:53:05,060 --> 00:53:06,690
to attend the class?

1014
00:53:06,690 --> 00:53:08,160
PROFESSOR: Feel free to
attend the class.

1015
00:53:08,160 --> 00:53:09,090
AUDIENCE: OK, where's
the schedule?

1016
00:53:09,090 --> 00:53:14,590
PROFESSOR: It is Tuesdays and
Thursdays in 26-100 at--

1017
00:53:14,590 --> 00:53:15,460
AUDIENCE: Is it on
the website?

1018
00:53:15,460 --> 00:53:19,690
PROFESSOR: It's on the website
at 2:30 to 4:00.

1019
00:53:19,690 --> 00:53:23,840
So Tuesdays and Thursdays 2:30
to 4:00, you're welcome to

1020
00:53:23,840 --> 00:53:27,380
come and learn all about
performance engineering.

1021
00:53:27,380 --> 00:53:28,290
Reed, did you have a question?

1022
00:53:28,290 --> 00:53:30,820
AUDIENCE: No, I guess I was
just going to say that in

1023
00:53:30,820 --> 00:53:36,085
regard to the feedback, we
TAs here have got that.

1024
00:53:36,085 --> 00:53:38,530
SAMAN AMARASINGHE: During class
last week most of the

1025
00:53:38,530 --> 00:53:41,219
TAs were students last year,
so they aren't learning

1026
00:53:41,219 --> 00:53:42,469
anything new.

1027
00:53:44,398 --> 00:53:47,670
AUDIENCE: I'm sorry,
where is the class?

1028
00:53:47,670 --> 00:53:50,160
PROFESSOR: It's in 26-100

1029
00:53:50,160 --> 00:53:52,164
AUDIENCE: So it's not here?

1030
00:53:52,164 --> 00:53:54,680
PROFESSOR: No.

1031
00:53:54,680 --> 00:53:58,000
So this is the situation, we
outgrew our classroom which

1032
00:53:58,000 --> 00:54:07,010
seated 60, and we had 85 or 90
students, so they put us into

1033
00:54:07,010 --> 00:54:09,700
the next smaller classroom
that we would fit into.

1034
00:54:09,700 --> 00:54:18,580
That was 26-100 which
fits 500.

1035
00:54:18,580 --> 00:54:24,860
Then we found that in 26-100
you needed a microphone for

1036
00:54:24,860 --> 00:54:27,550
the students to hear you, even
though we had them all crowded

1037
00:54:27,550 --> 00:54:30,230
into one quarter of the
auditorium, you still then--

1038
00:54:30,230 --> 00:54:32,420
just the structure of it-- you
needed a microphone, so they

1039
00:54:32,420 --> 00:54:36,620
said, "That will be $85 a
lecture." And you say, "What

1040
00:54:36,620 --> 00:54:38,766
do you mean $85 a lecture?"

1041
00:54:38,766 --> 00:54:41,100
SAMAN AMARASINGHE: Someone has
to walk in just to turn on--

1042
00:54:41,100 --> 00:54:43,510
PROFESSOR: To turn
on thing thing.

1043
00:54:43,510 --> 00:54:46,010
So, anyway we sorted all this
out OK, but it was sort of

1044
00:54:46,010 --> 00:54:51,750
funny that you're charging us
for being in a room that we

1045
00:54:51,750 --> 00:54:52,940
have no choice as to be in?

1046
00:54:52,940 --> 00:54:54,864
Anyway it was very funny.

1047
00:54:54,864 --> 00:54:57,691
AUDIENCE: Are your lectures
video taped are they

1048
00:54:57,691 --> 00:54:58,290
available--

1049
00:54:58,290 --> 00:54:59,420
PROFESSOR: They are
videotaped.

1050
00:54:59,420 --> 00:55:04,350
We are not planning to put them
up quick because what

1051
00:55:04,350 --> 00:55:06,860
that does is discourages
students from attending the

1052
00:55:06,860 --> 00:55:11,030
lectures, as you can imagine.

1053
00:55:11,030 --> 00:55:14,800
SAMAN AMARASINGHE: Mainly for
OCW OpenCourseWare So they

1054
00:55:14,800 --> 00:55:16,640
basically they could go to
OpenCourseWare they will

1055
00:55:16,640 --> 00:55:18,825
process it and they have to go
through a lot of legal stuff

1056
00:55:18,825 --> 00:55:20,640
and make sure the
named are right.

1057
00:55:20,640 --> 00:55:22,520
PROFESSOR: Are right
and so forth, yeah.

1058
00:55:22,520 --> 00:55:25,870
There is a bunch
of stuff there.

1059
00:55:25,870 --> 00:55:33,160
Good, so it says final words
here but they aren't really

1060
00:55:33,160 --> 00:55:34,630
final, because we still
have Eric to talk

1061
00:55:34,630 --> 00:55:40,130
about the first project.

1062
00:55:40,130 --> 00:55:44,350
But the feedback from the
students last year was that

1063
00:55:44,350 --> 00:55:47,480
the MIT POSSE was one thing that
made this one of their

1064
00:55:47,480 --> 00:55:48,410
favorite classes.

1065
00:55:48,410 --> 00:55:53,230
It was getting that kind of
seasoned feedback in a very

1066
00:55:53,230 --> 00:56:03,520
small group setting when you
look at the student faculty

1067
00:56:03,520 --> 00:56:06,730
ratio, that's one thing you're
always battling.

1068
00:56:06,730 --> 00:56:11,570
especially at MIT, where we are
in a very popular major,

1069
00:56:11,570 --> 00:56:16,060
and so the ability to recruit
all you folks to help that

1070
00:56:16,060 --> 00:56:20,400
ratio in favor of the students
is really very much

1071
00:56:20,400 --> 00:56:24,590
appreciated by students and
by us, so enjoy the term.

1072
00:56:24,590 --> 00:56:28,000
This is really rewarding the
people who have done it before

1073
00:56:28,000 --> 00:56:31,050
we had just tremendously
positive feedback from them

1074
00:56:31,050 --> 00:56:36,080
about just how rewarding it was
to work with these young

1075
00:56:36,080 --> 00:56:37,172
programmers.

1076
00:56:37,172 --> 00:56:39,806
SAMAN AMARASINGHE: They are very
smart people, you can see

1077
00:56:39,806 --> 00:56:41,630
the changes, you will see
the you impact on them.

1078
00:56:41,630 --> 00:56:44,501
You will see you're molding
these people into better

1079
00:56:44,501 --> 00:56:47,310
programmers, so that's
the fun part.

1080
00:56:47,310 --> 00:56:49,280
PROFESSOR: So Eric is now going
to talk a little bit

1081
00:56:49,280 --> 00:56:53,550
about project one, and this is
similar to what we will do,

1082
00:56:53,550 --> 00:56:55,750
although most of you will
probably be on the phone

1083
00:56:55,750 --> 00:57:01,980
unless you heed Barry's advice,
for the future one.

1084
00:57:01,980 --> 00:57:04,530
So I'll get out of your way.

1085
00:57:04,530 --> 00:57:08,760
ERIC: So the project one this
is, I think, the one project

1086
00:57:08,760 --> 00:57:12,980
that was substantially different
from last year.

1087
00:57:12,980 --> 00:57:17,110
So, the code for this
project we, the TAs,

1088
00:57:17,110 --> 00:57:18,360
coded up this semester.

1089
00:57:23,020 --> 00:57:27,660
Did we give out the hand outs,
Saman, or Charles?

1090
00:57:27,660 --> 00:57:29,800
Yeah so these are the--

1091
00:57:29,800 --> 00:57:39,562
PROFESSOR: So this is the actual
assignment and we'll

1092
00:57:39,562 --> 00:57:40,890
share this with you,
plus the reference

1093
00:57:40,890 --> 00:57:42,490
implementation, I think.

1094
00:57:48,350 --> 00:57:51,620
ERIC: Well we'll send out the
reference implementation

1095
00:57:51,620 --> 00:57:52,870
tonight then.

1096
00:57:55,100 --> 00:57:58,870
In fact, now people have already
done their betas for

1097
00:57:58,870 --> 00:58:01,580
project one.

1098
00:58:01,580 --> 00:58:06,480
Project one has two parts, it's
a part called Every Bit

1099
00:58:06,480 --> 00:58:09,890
Counts and a part called
Tiling a Torus with

1100
00:58:09,890 --> 00:58:11,140
Pentominoes.

1101
00:58:12,950 --> 00:58:24,590
So the first part it's an
abstract data types of

1102
00:58:24,590 --> 00:58:30,100
modeling and bit array, packed
bit array and they are a given

1103
00:58:30,100 --> 00:58:33,990
a couple of tasks to do on
long strings of bits.

1104
00:58:33,990 --> 00:58:37,330
So you might have eight million
bits and there are two

1105
00:58:37,330 --> 00:58:41,890
functions to rotate the
substring of the bits by some

1106
00:58:41,890 --> 00:58:45,940
amount to the left or right, and
the other operation is to

1107
00:58:45,940 --> 00:58:48,910
count how many flipped
bits there

1108
00:58:48,910 --> 00:58:50,710
are in a given substring.

1109
00:58:50,710 --> 00:58:56,040
So the specific interface for
this, this an excerpt without

1110
00:58:56,040 --> 00:59:01,915
the comments from the header
file of this C module.

1111
00:59:05,220 --> 00:59:09,730
There is a couple of accessors
which accesses bits

1112
00:59:09,730 --> 00:59:15,700
individually those are not,
well those accessors are

1113
00:59:15,700 --> 00:59:18,540
currently used to implement,
in the reference

1114
00:59:18,540 --> 00:59:26,070
implementation, the rotate and
count flips operations.

1115
00:59:26,070 --> 00:59:32,110
So what they will need to do
is to go into the C module,

1116
00:59:32,110 --> 00:59:38,800
the implementation, and change
these functions, to basically

1117
00:59:38,800 --> 00:59:41,980
be 10,000 times faster, or
whatever, I can't remember

1118
00:59:41,980 --> 00:59:43,380
what they actually got.

1119
00:59:43,380 --> 00:59:46,730
In particular the rotate
operation is incredibly slow,

1120
00:59:46,730 --> 00:59:49,040
there's one constraint for them
and we're saying that,

1121
00:59:49,040 --> 00:59:52,090
well imagine that this is on the
cell phone or something,

1122
00:59:52,090 --> 00:59:57,520
where you have a really big
bit array, but you don't

1123
00:59:57,520 --> 01:00:03,060
really have very much more
memory to consume beyond that

1124
01:00:03,060 --> 01:00:03,990
big bit array.

1125
01:00:03,990 --> 01:00:08,420
So we're asking them to only
do this using a constant

1126
01:00:08,420 --> 01:00:11,700
amount of memory.

1127
01:00:11,700 --> 01:00:15,270
So that's the first problem
with these two parts, the

1128
01:00:15,270 --> 01:00:18,500
rotate and the count flips.

1129
01:00:18,500 --> 01:00:23,010
Any problem, questions about
that particular part?

1130
01:00:23,010 --> 01:00:25,836
Does it seem clear what?

1131
01:00:25,836 --> 01:00:27,410
AUDIENCE: What does the
count flips do?

1132
01:00:27,410 --> 01:00:30,980
ERIC: Oh yeah, so I should've
swap those two slides.

1133
01:00:30,980 --> 01:00:34,740
So, if you have a bit string,
suppose nine bits or

1134
01:00:34,740 --> 01:00:38,470
something, 1, 2, 3, 4, 5, 6, 7,
8, that would have to be 8.

1135
01:00:43,780 --> 01:00:48,110
If this is the substring you
want to count, then you count

1136
01:00:48,110 --> 01:00:54,090
transitions from zero to
one, or one to zero.

1137
01:00:54,090 --> 01:00:58,790
And there's some new tricks you
can do by for instance,

1138
01:00:58,790 --> 01:00:59,550
considering six--

1139
01:00:59,550 --> 01:01:04,230
AUDIENCE: Count the number of
runs, of consecutive value.

1140
01:01:04,230 --> 01:01:06,622
ERIC: Yeah, the number
of runs.

1141
01:01:06,622 --> 01:01:07,945
AUDIENCE: Plus plus one--

1142
01:01:07,945 --> 01:01:09,270
or minus one, yeah.

1143
01:01:09,270 --> 01:01:10,660
ERIC: That's right.

1144
01:01:10,660 --> 01:01:13,280
And you don't count the
beginning or the end as a

1145
01:01:13,280 --> 01:01:17,160
transition, so in this
particular substring there is

1146
01:01:17,160 --> 01:01:20,130
one there, one there,
and one there.

1147
01:01:20,130 --> 01:01:22,670
And it's not a substrings, it's
always substrings, it's

1148
01:01:22,670 --> 01:01:28,940
not the entire string, and you
can see that for instance, you

1149
01:01:28,940 --> 01:01:32,260
give us an argument, the bit
array and you say where the

1150
01:01:32,260 --> 01:01:39,580
starting offset and the number
of bits that the substring

1151
01:01:39,580 --> 01:01:41,400
that the substring is
and that's where the

1152
01:01:41,400 --> 01:01:42,300
operation is done.

1153
01:01:42,300 --> 01:01:47,100
So our testing routines will
do lots of rotations in

1154
01:01:47,100 --> 01:01:50,184
different parts of
that substring.

1155
01:01:50,184 --> 01:01:52,047
AUDIENCE: For the memory
constraint, do you have a

1156
01:01:52,047 --> 01:01:55,500
fixed size that they're
allowed to use or?

1157
01:01:55,500 --> 01:01:57,330
ERIC: We decided against
the fixed size.

1158
01:01:57,330 --> 01:02:04,630
We just say don't use malloc,
and you can allocate constant

1159
01:02:04,630 --> 01:02:08,100
amounts of memory, and the thing
is if they choose to

1160
01:02:08,100 --> 01:02:13,720
have a 16 megabyte or four
gigabyte lookup table then

1161
01:02:13,720 --> 01:02:15,110
their performance will
suffer anyway.

1162
01:02:18,560 --> 01:02:19,696
So yep?

1163
01:02:19,696 --> 01:02:21,710
AUDIENCE: What is the computer
architecture?

1164
01:02:21,710 --> 01:02:22,410
ERIC: What's that?

1165
01:02:22,410 --> 01:02:24,550
AUDIENCE: What is the computer
architecture?

1166
01:02:24,550 --> 01:02:26,890
SAMAN AMARASINGHE: We
are running on--

1167
01:02:26,890 --> 01:02:34,510
we got this donation from both
Intel and Dell, we have 16

1168
01:02:34,510 --> 01:02:40,390
machine-segments, each with two
six core processors and 48

1169
01:02:40,390 --> 01:02:41,235
gigs of memory.

1170
01:02:41,235 --> 01:02:43,640
So they're doing it on 12
cores so it becomes

1171
01:02:43,640 --> 01:02:46,116
interesting, and you got a
parallel 740 gigs, so we have

1172
01:02:46,116 --> 01:02:48,149
a lot of memory in these kinds
of things and we'll be asking

1173
01:02:48,149 --> 01:02:48,695
them to run through that.

1174
01:02:48,695 --> 01:02:54,100
So these were the latest
what's the word?

1175
01:02:54,100 --> 01:02:54,770
PROFESSOR: Core i7.

1176
01:02:54,770 --> 01:02:55,620
SAMAN AMARASINGHE: Core i7s.

1177
01:02:55,620 --> 01:02:56,830
PROFESSOR: Nehalem.

1178
01:02:56,830 --> 01:02:59,540
ERIC: For this first project,
we're asking them specifically

1179
01:02:59,540 --> 01:03:02,810
not to parallelize.

1180
01:03:02,810 --> 01:03:05,140
AUDIENCE: It's all on
Windows or Linux?

1181
01:03:05,140 --> 01:03:05,940
ERIC: Linux.

1182
01:03:05,940 --> 01:03:06,856
AUDIENCE: Linux?

1183
01:03:06,856 --> 01:03:09,610
ERIC: Yeah.

1184
01:03:09,610 --> 01:03:14,430
So the idea here is to exploit
bit operation and in

1185
01:03:14,430 --> 01:03:15,710
particular in rotates.

1186
01:03:15,710 --> 01:03:18,220
The reference implementation
does the really stupid thing

1187
01:03:18,220 --> 01:03:25,310
of you want sort of 4,000 bits
to the right rotates, well

1188
01:03:25,310 --> 01:03:29,560
I'll do it one at a time,
that's the reference

1189
01:03:29,560 --> 01:03:30,810
implementation.

1190
01:03:32,620 --> 01:03:36,020
But they're only allowed to us
a constant amount of memory,

1191
01:03:36,020 --> 01:03:40,300
so there is certain amount of
tricks you have to do to do it

1192
01:03:40,300 --> 01:03:42,946
in a more efficient way.

1193
01:03:42,946 --> 01:03:45,862
AUDIENCE: Do you stress in the
course about portable data

1194
01:03:45,862 --> 01:03:48,535
code from one operating
system to another, one

1195
01:03:48,535 --> 01:03:51,010
machine to the other.

1196
01:03:51,010 --> 01:03:54,550
PROFESSOR: This is where we
want you to stress the

1197
01:03:54,550 --> 01:03:57,380
importance of it, because that's
not something that

1198
01:03:57,380 --> 01:04:01,810
we're in a position to do or
enforce, or what have you, OK?

1199
01:04:05,000 --> 01:04:08,140
We let them assume for this
problem, for example, that the

1200
01:04:08,140 --> 01:04:10,000
machine they're working
on is Little Endian.

1201
01:04:10,000 --> 01:04:13,250
We talked about the issue, but
we did not insist that they

1202
01:04:13,250 --> 01:04:17,850
wrote code that would be that
would port to a Big Endian

1203
01:04:17,850 --> 01:04:22,500
machine, because they're running
on the Intel machines.

1204
01:04:22,500 --> 01:04:27,030
But this is exactly the kind
of thing where code quality

1205
01:04:27,030 --> 01:04:32,630
would say, portability,
maintainability, readability,

1206
01:04:32,630 --> 01:04:36,920
all these kinds of things, this
is exactly the kind of

1207
01:04:36,920 --> 01:04:39,770
thing we want you to say.

1208
01:04:39,770 --> 01:04:42,700
You say "Hey, you did it like
this, in fact did you know

1209
01:04:42,700 --> 01:04:46,930
that without sacrificing
anything in performance, you

1210
01:04:46,930 --> 01:04:49,600
could have made it portable from
one operating system to

1211
01:04:49,600 --> 01:04:54,450
another?" And then you could
talk about those issues, and

1212
01:04:54,450 --> 01:04:57,500
that's absolutely super,
to do that.

1213
01:04:57,500 --> 01:05:02,420
But we are not spending a lot
of class time doing that,

1214
01:05:02,420 --> 01:05:04,770
we're really focusing on the
performance engineering part

1215
01:05:04,770 --> 01:05:06,120
of the course.

1216
01:05:06,120 --> 01:05:07,910
ERIC: The reference
implementation should be

1217
01:05:07,910 --> 01:05:15,940
portable, so this should be
portable, although we did make

1218
01:05:15,940 --> 01:05:19,900
sure here, for instance, in the
reference representation

1219
01:05:19,900 --> 01:05:23,620
of bit array here, that the
order of the bits within each

1220
01:05:23,620 --> 01:05:26,320
bite happened to coincide
with the low end

1221
01:05:26,320 --> 01:05:27,410
ideas of these machines.

1222
01:05:27,410 --> 01:05:31,550
So that if you happen to cast it
to a 64-bit integer on each

1223
01:05:31,550 --> 01:05:35,900
of the bytes in the array then
you would get something that

1224
01:05:35,900 --> 01:05:43,300
was easy to work with on a
low end in architecture.

1225
01:05:43,300 --> 01:05:47,060
But the reference implementation
is portable

1226
01:05:47,060 --> 01:05:50,940
itself, or should be, so tell
us any kind of problems with

1227
01:05:50,940 --> 01:05:53,760
the reference implementation
like that.

1228
01:05:53,760 --> 01:05:56,540
The next problem is based
on the puzzle,

1229
01:05:56,540 --> 01:05:59,940
it's a puzzle solver.

1230
01:05:59,940 --> 01:06:02,920
It's this puzzle that I'd
never heard of before.

1231
01:06:02,920 --> 01:06:07,040
Apparently, if you generalize
dominoes you get Pentominoes

1232
01:06:07,040 --> 01:06:10,080
and the five end cases.

1233
01:06:10,080 --> 01:06:16,080
So there are this many
configurations of dominoes

1234
01:06:16,080 --> 01:06:19,900
with five squares on
them, I guess.

1235
01:06:19,900 --> 01:06:25,250
And the pentominoes puzzle is
you're given an eight by eight

1236
01:06:25,250 --> 01:06:29,900
board with four squares crossed
out, and now you're

1237
01:06:29,900 --> 01:06:35,210
supposed to arrange these so
that the entire board is

1238
01:06:35,210 --> 01:06:37,040
filled up, and only--

1239
01:06:37,040 --> 01:06:37,400
what's that?

1240
01:06:37,400 --> 01:06:38,540
SAMAN AMARASINGHE: You can
do flips of these--

1241
01:06:38,540 --> 01:06:39,280
ERIC: Oh, right.

1242
01:06:39,280 --> 01:06:41,220
You can do flips, you rotate

1243
01:06:41,220 --> 01:06:43,620
SAMAN AMARASINGHE: And
they will dissipate

1244
01:06:43,620 --> 01:06:45,600
and all those things.

1245
01:06:45,600 --> 01:06:50,860
ERIC: Right so the task is
find all the solutions,

1246
01:06:50,860 --> 01:06:56,800
although I believe in our
reference implementation that

1247
01:06:56,800 --> 01:07:01,660
was too fast, so we decided to
generalize the puzzle to the

1248
01:07:01,660 --> 01:07:08,140
toroidal case, where the board
wraps around the edges, just

1249
01:07:08,140 --> 01:07:10,460
to make it take a little
longer, to do.

1250
01:07:10,460 --> 01:07:12,300
PROFESSOR: Like space
boards right?

1251
01:07:12,300 --> 01:07:14,953
You go off the right edge you
come in the left edge.

1252
01:07:14,953 --> 01:07:16,336
AUDIENCE: Top and bottom also?

1253
01:07:16,336 --> 01:07:18,650
PROFESSOR: Top and bottom
also, yeah.

1254
01:07:18,650 --> 01:07:21,190
ERIC: So these two are
both examples of

1255
01:07:21,190 --> 01:07:23,060
solutions to this puzzle.

1256
01:07:23,060 --> 01:07:23,680
AUDIENCE: I've got
a question here.

1257
01:07:23,680 --> 01:07:24,840
ERIC: Yep.

1258
01:07:24,840 --> 01:07:26,260
AUDIENCE: Are you allowed
to put the empty space

1259
01:07:26,260 --> 01:07:27,320
where ever you want?

1260
01:07:27,320 --> 01:07:33,020
ERIC: Well, that's the
input to the solver.

1261
01:07:33,020 --> 01:07:34,880
SAMAN AMARASINGHE: Given
these empty spaces--

1262
01:07:34,880 --> 01:07:36,740
AUDIENCE: OK, and then
it fills in the rest.

1263
01:07:36,740 --> 01:07:37,205
ERIC: That's right.

1264
01:07:37,205 --> 01:07:38,920
Of course you can put
empty spaces so

1265
01:07:38,920 --> 01:07:40,300
that it can't solved.

1266
01:07:40,300 --> 01:07:42,175
And then they have to correctly
determine that

1267
01:07:42,175 --> 01:07:42,490
there's no answer.

1268
01:07:42,490 --> 01:07:43,340
PROFESSOR: That there's
no answer.

1269
01:07:43,340 --> 01:07:44,850
AUDIENCE: Right.

1270
01:07:44,850 --> 01:07:48,310
ERIC: And, also I believe the
reference solution takes days,

1271
01:07:48,310 --> 01:07:49,910
for certain.

1272
01:07:49,910 --> 01:07:54,220
To find all the solutions of
certain configurations of the

1273
01:07:54,220 --> 01:07:56,520
initial four dots.

1274
01:07:56,520 --> 01:07:59,720
So there's an option to the
program we give them, to just

1275
01:07:59,720 --> 01:08:01,390
find the first 2,000
or something.

1276
01:08:01,390 --> 01:08:03,440
PROFESSOR: So once again you can
see this is conducive to

1277
01:08:03,440 --> 01:08:07,460
bit tricks, where you represent
the board as a

1278
01:08:07,460 --> 01:08:13,330
64-bit word and then do masking
operations, and so

1279
01:08:13,330 --> 01:08:15,800
forth, to determine whether
a piece fits

1280
01:08:15,800 --> 01:08:18,060
and do clever shifting.

1281
01:08:18,060 --> 01:08:21,680
It's easy to shift a piece down
one row, where you're

1282
01:08:21,680 --> 01:08:27,029
trying it out, because that's
just a shift by eight, but how

1283
01:08:27,029 --> 01:08:32,109
do you shift it horizontally, to
come around on the other--

1284
01:08:32,109 --> 01:08:35,200
So they have to do some
shifting, some masking--

1285
01:08:35,200 --> 01:08:40,859
So anyway, the first project
is all about thinking about

1286
01:08:40,859 --> 01:08:43,074
bit representations of
things, and so forth.

1287
01:08:43,074 --> 01:08:45,609
ERIC: In fact, we give them a
solver that we don't really--

1288
01:08:45,609 --> 01:08:50,960
well, a searcher, routine to
search the space of possible

1289
01:08:50,960 --> 01:08:54,160
solutions, that we don't really
expect them to change,

1290
01:08:54,160 --> 01:08:56,810
but they can change it
if they want to do.

1291
01:08:56,810 --> 01:09:04,689
So, the interface here is
basically a board data

1292
01:09:04,689 --> 01:09:08,340
structure that they're free
to change the internal

1293
01:09:08,340 --> 01:09:09,689
representations of.

1294
01:09:09,689 --> 01:09:13,510
Or did we somehow prohibit
that due to testing?

1295
01:09:13,510 --> 01:09:13,810
No?

1296
01:09:13,810 --> 01:09:16,649
No, no, no, that's the
whole point, right.

1297
01:09:16,649 --> 01:09:23,149
So again, you have this basic
accessor for use by the

1298
01:09:23,149 --> 01:09:25,330
testing routines.

1299
01:09:25,330 --> 01:09:29,410
But then what you really need
to, well, you need to change

1300
01:09:29,410 --> 01:09:33,000
basically the entire
implementation of all of this,

1301
01:09:33,000 --> 01:09:35,180
if you're changing the
representation of the board,

1302
01:09:35,180 --> 01:09:37,770
for instance.

1303
01:09:37,770 --> 01:09:42,220
But this is the function that
should be running faster after

1304
01:09:42,220 --> 01:09:45,899
you're done, so I guess that
comment is misleading.

1305
01:09:45,899 --> 01:09:49,189
This is the function that is
supposed to run a lot faster

1306
01:09:49,189 --> 01:09:50,850
when you're done.

1307
01:09:50,850 --> 01:09:56,470
There is actual comments
in the header file.

1308
01:09:56,470 --> 01:09:58,050
So right, you give
it a function

1309
01:09:58,050 --> 01:10:00,688
pointer to a call back.

1310
01:10:00,688 --> 01:10:03,650
PROFESSOR: Now, one sort of
standard thing we decided

1311
01:10:03,650 --> 01:10:08,060
we're doing is, we're not trying
to write both 32 and

1312
01:10:08,060 --> 01:10:12,070
64-bit code in the classroom,
we're just going to do 64-bit.

1313
01:10:12,070 --> 01:10:14,880
So just one more level.

1314
01:10:14,880 --> 01:10:17,850
In practice you would want to
have stuff that runs both on

1315
01:10:17,850 --> 01:10:22,190
32 and 64, but for the most part
it's fine if they just

1316
01:10:22,190 --> 01:10:25,622
have it running on 64-bit.

1317
01:10:25,622 --> 01:10:30,460
ERIC: Right, so these by the
way are the initial four

1318
01:10:30,460 --> 01:10:32,510
points that are the input
to the puzzle.

1319
01:10:35,860 --> 01:10:40,660
I believe that's the
problem set one.

1320
01:10:40,660 --> 01:10:41,810
Questions about, yeah?

1321
01:10:41,810 --> 01:10:45,802
AUDIENCE: Can students submit
more than one answer?

1322
01:10:45,802 --> 01:10:46,800
PROFESSOR: No.

1323
01:10:46,800 --> 01:10:51,570
Nope, they got to decide
what they're doing.

1324
01:10:51,570 --> 01:10:53,046
AUDIENCE: I guess I have a
question about the answer.

1325
01:10:53,046 --> 01:10:53,538
ERIC: Yeah.

1326
01:10:53,538 --> 01:10:56,711
AUDIENCE: Is an answer that is
probabilistically correct, I

1327
01:10:56,711 --> 01:11:00,740
mean like, it will sometimes
when you test it, you have it

1328
01:11:00,740 --> 01:11:03,390
pass all the test cases, but
mine isn't guaranteed to

1329
01:11:03,390 --> 01:11:05,544
necessarily always solve all
test cases is that OK?

1330
01:11:05,544 --> 01:11:08,890
ERIC: If they can conceal that
to us, then I think they--

1331
01:11:08,890 --> 01:11:12,060
PROFESSOR: They deserve
credit.

1332
01:11:12,060 --> 01:11:16,210
ERIC: Keep in mind that the
other half of the problem set

1333
01:11:16,210 --> 01:11:20,160
is to write test cases that
will catch as many obscure

1334
01:11:20,160 --> 01:11:24,100
bugs in the other students'
code as possible.

1335
01:11:24,100 --> 01:11:27,270
So they run the risk of
competing against--

1336
01:11:27,270 --> 01:11:29,000
PROFESSOR: They lose extra
points if they don't pass

1337
01:11:29,000 --> 01:11:32,240
their own tests.

1338
01:11:32,240 --> 01:11:33,853
AUDIENCE: They each need
to write some tests

1339
01:11:33,853 --> 01:11:35,016
that will be as--

1340
01:11:35,016 --> 01:11:36,125
PROFESSOR: Yeah,
so then they--

1341
01:11:36,125 --> 01:11:36,680
AUDIENCE: They exercise
somebody else's.

1342
01:11:36,680 --> 01:11:38,160
PROFESSOR: --to somebody
else's, yeah.

1343
01:11:38,160 --> 01:11:39,500
SAMAN AMARASINGHE: We are
running all the tests against

1344
01:11:39,500 --> 01:11:40,850
everybody else.

1345
01:11:40,850 --> 01:11:42,935
PROFESSOR: And then for the
final version we give them the

1346
01:11:42,935 --> 01:11:47,720
full regression suite of the
whole class, so they have very

1347
01:11:47,720 --> 01:11:49,960
good confidence, and we good
confidence that they're

1348
01:11:49,960 --> 01:11:53,080
handing in something
that is correct.

1349
01:11:55,740 --> 01:11:58,450
SAMAN AMARASINGHE: OK, so you
want to open up for--

1350
01:11:58,450 --> 01:12:00,521
PROFESSOR: For questions
or comments.

1351
01:12:00,521 --> 01:12:02,030
SAMAN AMARASINGHE: Especially,
I won't even mind the people

1352
01:12:02,030 --> 01:12:06,965
who did it last time, last time
to provide some of your

1353
01:12:06,965 --> 01:12:08,945
feedback on how we can...

1354
01:12:08,945 --> 01:12:10,430
[BUZZING NOISE]

1355
01:12:10,430 --> 01:12:11,420
PROFESSOR: Don't want
to do that?

1356
01:12:11,420 --> 01:12:13,895
SAMAN AMARASINGHE: Yeah,

1357
01:12:13,895 --> 01:12:16,370
PROFESSOR: I was trying
to turn on the lights.

1358
01:12:16,370 --> 01:12:18,450
Do we have more lights
we can turn on?

1359
01:12:23,813 --> 01:12:25,801
SAMAN AMARASINGHE: Also, if you
could turn these on, too?

1360
01:12:25,801 --> 01:12:27,300
PROFESSOR: Good.

1361
01:12:27,300 --> 01:12:30,598
Yeah, so comments?

1362
01:12:30,598 --> 01:12:33,574
AUDIENCE: I want to say that's
why I was a master last year,

1363
01:12:33,574 --> 01:12:36,054
and I had a great time, but
I figured I'd stay--

1364
01:12:36,054 --> 01:12:37,542
[INTERPOSING VOICES]

1365
01:12:37,542 --> 01:12:38,534
PROFESSOR: Yeah, could
you stand up so

1366
01:12:38,534 --> 01:12:39,526
people can hear you?

1367
01:12:39,526 --> 01:12:40,022
Thanks.

1368
01:12:40,022 --> 01:12:41,014
SAMAN AMARASINGHE:
Give him a mic.

1369
01:12:41,014 --> 01:12:43,990
Give him a mic because I
think it'll be good--

1370
01:12:43,990 --> 01:12:46,966
PROFESSOR: It'll be good
to have these-- yeah.

1371
01:12:46,966 --> 01:12:47,462
All right?

1372
01:12:47,462 --> 01:12:47,958
AUDIENCE: All right.

1373
01:12:47,958 --> 01:12:49,470
Thank you.

1374
01:12:49,470 --> 01:12:55,070
So the first thing I found
really helpful was to take the

1375
01:12:55,070 --> 01:12:57,060
reference solution and actually
diff what the student

1376
01:12:57,060 --> 01:12:59,130
provide because they often just
provided a solution, and

1377
01:12:59,130 --> 01:13:00,800
if you don't know what they
started from, it was hard to

1378
01:13:00,800 --> 01:13:01,760
tell what they'd
actually done.

1379
01:13:01,760 --> 01:13:04,760
So diffing the two, that was
a good place to start.

1380
01:13:04,760 --> 01:13:08,190
And then I found incredibly
helpful just to spend 15 or 20

1381
01:13:08,190 --> 01:13:11,430
minutes prior to actually
meeting with them, looking at

1382
01:13:11,430 --> 01:13:13,610
the code and writing like two
or three or four things to

1383
01:13:13,610 --> 01:13:14,745
talk to them about.

1384
01:13:14,745 --> 01:13:17,090
And it might sound like it's
going to be highfalutin and

1385
01:13:17,090 --> 01:13:20,020
stuff, but it was like they're
using their returning function

1386
01:13:20,020 --> 01:13:23,120
pointers to local variables,
stuff like that.

1387
01:13:23,120 --> 01:13:27,590
It was really like what the hell
the makefiles were doing,

1388
01:13:27,590 --> 01:13:30,010
for example, is something
that I think they really

1389
01:13:30,010 --> 01:13:32,960
appreciated me telling
them that didn't get

1390
01:13:32,960 --> 01:13:34,210
talked about in class.

1391
01:13:36,230 --> 01:13:37,800
Especially once I got a good
rapport with them, they just

1392
01:13:37,800 --> 01:13:40,380
ask questions, and I spent the
whole time answering more

1393
01:13:40,380 --> 01:13:41,920
practical stuff about
the problem.

1394
01:13:41,920 --> 01:13:44,780
We had a good discussion, so
that's what I would suggest.

1395
01:13:44,780 --> 01:13:48,360
PROFESSOR: Thank you, that's
great feedback.

1396
01:13:48,360 --> 01:13:50,730
Yeah, as I say, don't
underestimate--

1397
01:13:50,730 --> 01:13:57,170
I mean, most people learn the
kinds of things you're saying,

1398
01:13:57,170 --> 01:14:02,480
but somebody told them that,
hey, these are practices that

1399
01:14:02,480 --> 01:14:05,760
really don't make sense in
a real software system.

1400
01:14:05,760 --> 01:14:08,210
AUDIENCE: People were, by the
time we got to the projects,

1401
01:14:08,210 --> 01:14:11,605
your standard pattern was highly
representative, a bunch

1402
01:14:11,605 --> 01:14:16,500
of flags you want to encode in
a bunch of fields, right?

1403
01:14:16,500 --> 01:14:18,215
And you've seen them a
couple times, it's

1404
01:14:18,215 --> 01:14:19,930
just a standard pattern.

1405
01:14:19,930 --> 01:14:21,530
PROFESSOR: Yeah, so one of the
things you'll find in this

1406
01:14:21,530 --> 01:14:23,960
first one is that they're very
confused about the difference

1407
01:14:23,960 --> 01:14:29,070
between unsigned and signed, and
how shifts work, and what

1408
01:14:29,070 --> 01:14:33,870
happens when, you know, how come
I shifted this thing left

1409
01:14:33,870 --> 01:14:36,320
33 bits and I got a zero.

1410
01:14:36,320 --> 01:14:37,310
Why?

1411
01:14:37,310 --> 01:14:41,350
I thought I was shifting a
64-bit value, but in fact,

1412
01:14:41,350 --> 01:14:45,760
they hadn't done 1LL,
they just did 1.

1413
01:14:45,760 --> 01:14:50,840
And so there are things like
that, where they don't--

1414
01:14:50,840 --> 01:14:58,100
very low hanging fruit, if
you will, to talk about.

1415
01:14:58,100 --> 01:15:00,580
AUDIENCE: Did you tell them
about valgrind by the way?

1416
01:15:00,580 --> 01:15:03,133
Like, why would programs crash
when they said they spent a

1417
01:15:03,133 --> 01:15:06,213
huge amount of time debugging
these crazy C programs when

1418
01:15:06,213 --> 01:15:08,460
they're not used to the compiler
not protecting them.

1419
01:15:08,460 --> 01:15:10,250
PROFESSOR: Actually, that's a
good point because we were

1420
01:15:10,250 --> 01:15:15,490
going to try to introduce--
maybe we should do that as

1421
01:15:15,490 --> 01:15:17,540
part of the next lecture,
spend a little

1422
01:15:17,540 --> 01:15:20,238
bit of time on valgrind.

1423
01:15:20,238 --> 01:15:22,470
SAMAN AMARASINGHE: Yeah.

1424
01:15:22,470 --> 01:15:24,060
PROFESSOR: Because the memory
checker there is really a

1425
01:15:24,060 --> 01:15:28,150
pretty useful tool for them
to get correct code.

1426
01:15:28,150 --> 01:15:28,960
AUDIENCE: I second that.

1427
01:15:28,960 --> 01:15:30,520
That thing has saved my
butt so many times.

1428
01:15:30,520 --> 01:15:31,770
PROFESSOR: So many
times, exactly.

1429
01:15:35,102 --> 01:15:39,635
AUDIENCE: I've heard that, but
more low-hanging fruit for

1430
01:15:39,635 --> 01:15:48,520
valgrind is to always compile a
-w all to just cache all the

1431
01:15:48,520 --> 01:15:50,750
warning and declare all warnings
as errors, and it

1432
01:15:50,750 --> 01:15:52,970
just makes--

1433
01:15:52,970 --> 01:15:54,315
PROFESSOR: I think that
we have that as a

1434
01:15:54,315 --> 01:15:55,230
default in our makefile.

1435
01:15:55,230 --> 01:15:55,680
Is that right?

1436
01:15:55,680 --> 01:15:56,960
ERIC: At least for the
first project.

1437
01:15:56,960 --> 01:15:59,350
PROFESSOR: The first project?

1438
01:15:59,350 --> 01:16:03,390
AUDIENCE: I think they should
understand that in industry

1439
01:16:03,390 --> 01:16:08,775
practice, if you don't do
that, you're a schmuck.

1440
01:16:08,775 --> 01:16:10,200
PROFESSOR: Right.

1441
01:16:10,200 --> 01:16:11,625
Yep.

1442
01:16:11,625 --> 01:16:16,170
Good, so that's good, and why,
in particular, the valgrind--

1443
01:16:16,170 --> 01:16:19,710
we discussed that last year,
and really actually, the

1444
01:16:19,710 --> 01:16:22,440
upcoming lecture's exactly
when we should do that.

1445
01:16:22,440 --> 01:16:24,570
SAMAN AMARASINGHE: Because
there's also another tool

1446
01:16:24,570 --> 01:16:26,240
called Dr. Memory.

1447
01:16:26,240 --> 01:16:27,960
PROFESSOR: OK, which
makes sense, yeah.

1448
01:16:32,800 --> 01:16:34,920
AUDIENCE: One issue that I
experienced a little last year

1449
01:16:34,920 --> 01:16:37,122
was that people they
specifically intend to write a

1450
01:16:37,122 --> 01:16:38,680
little test for their code.

1451
01:16:38,680 --> 01:16:41,526
They've mostly relied on a few
runs by hand, then they wrote

1452
01:16:41,526 --> 01:16:45,110
a progression producing things
that they ran earlier.

1453
01:16:45,110 --> 01:16:47,340
I guess that now you're actually
encouraging them to

1454
01:16:47,340 --> 01:16:47,590
actually have a test suite.

1455
01:16:47,590 --> 01:16:50,840
PROFESSOR: Yeah, well, now they
get points off if they

1456
01:16:50,840 --> 01:16:53,960
didn't write enough test that
somebody else's code passed it

1457
01:16:53,960 --> 01:16:54,960
that had a bug.

1458
01:16:54,960 --> 01:16:58,740
AUDIENCE: And in this case the
testing run will be as far as

1459
01:16:58,740 --> 01:17:02,830
the first turn in, and then the
second turn in is just you

1460
01:17:02,830 --> 01:17:05,170
have a version to run
against and then

1461
01:17:05,170 --> 01:17:06,010
just need to optimize.

1462
01:17:06,010 --> 01:17:07,080
PROFESSOR: Right,
that's right.

1463
01:17:07,080 --> 01:17:09,132
SAMAN AMARASINGHE: So first,
about the actual tests they

1464
01:17:09,132 --> 01:17:12,100
have write a lot of tests
because that will help, and

1465
01:17:12,100 --> 01:17:14,200
the second, then you give
them all the tests.

1466
01:17:14,200 --> 01:17:17,280
So they will have a lot of test
suite to run and then of

1467
01:17:17,280 --> 01:17:19,726
course we have a lot of number
of points we'll deduct of you

1468
01:17:19,726 --> 01:17:21,210
actually fail those test.

1469
01:17:21,210 --> 01:17:22,100
Because they have no excuse.

1470
01:17:22,100 --> 01:17:23,610
PROFESSOR: There's no excuse
at that point, it's just a

1471
01:17:23,610 --> 01:17:24,340
question of having--

1472
01:17:24,340 --> 01:17:28,360
AUDIENCE: What performance and
measurement tools are you

1473
01:17:28,360 --> 01:17:30,160
going to be using this year?

1474
01:17:30,160 --> 01:17:32,955
SAMAN AMARASINGHE: So, right
now, we are going to give them

1475
01:17:32,955 --> 01:17:38,690
perf because what we found was,
the process of ECUT is so

1476
01:17:38,690 --> 01:17:42,090
new a lot of performance tools
don't have-- like OperaFile

1477
01:17:42,090 --> 01:17:45,200
didn't work, because they
haven't been ported properly.

1478
01:17:45,200 --> 01:17:46,500
There's no port for it yet.

1479
01:17:46,500 --> 01:17:49,680
So perf we are going to use, and
we are thinking of giving

1480
01:17:49,680 --> 01:17:51,830
them gprof in there.

1481
01:17:51,830 --> 01:17:56,585
And then last year gave them
couple Pintools we didn't ask

1482
01:17:56,585 --> 01:17:58,880
them to write anything but for
example, account number

1483
01:17:58,880 --> 01:18:01,980
instruction or couple of
tools they do that.

1484
01:18:01,980 --> 01:18:05,140
Those are main tools you get,
and also we need to go to

1485
01:18:05,140 --> 01:18:09,400
Cilk, you'll do a bunch of
Cilk tools in there.

1486
01:18:09,400 --> 01:18:12,170
AUDIENCE: Everyone last year,
they were given VTune, I think

1487
01:18:12,170 --> 01:18:15,500
it was, it was too hard
for them to use.

1488
01:18:15,500 --> 01:18:17,610
PROFESSOR: Yeah, that was too
hard for them to use because

1489
01:18:17,610 --> 01:18:21,040
they have to use the machines
remotely, and VTune and is an

1490
01:18:21,040 --> 01:18:24,750
interactive tool, and so that
just made it very complicated

1491
01:18:24,750 --> 01:18:25,460
to do things.

1492
01:18:25,460 --> 01:18:28,820
So instead we're going to go
with a something that has

1493
01:18:28,820 --> 01:18:33,030
textual output, and is easy,
therefore, to run from command

1494
01:18:33,030 --> 01:18:37,155
line and has all the advantages
of running things

1495
01:18:37,155 --> 01:18:39,160
that you get when you run things
from command line.

1496
01:18:42,888 --> 01:18:47,050
AUDIENCE: So a logistical
question so, meeting on MIT is

1497
01:18:47,050 --> 01:18:49,920
fine, but where are there
designated places to meet?

1498
01:18:49,920 --> 01:18:51,870
SAMAN AMARASINGHE: We will
work with student to find

1499
01:18:51,870 --> 01:18:54,070
places for them.

1500
01:18:54,070 --> 01:18:57,790
For example, there are locations
for PSS students to

1501
01:18:57,790 --> 01:19:00,090
meet, and we are going
to get them arranged.

1502
01:19:00,090 --> 01:19:04,840
So if in the organizing you guys
can create probably an

1503
01:19:04,840 --> 01:19:05,995
online scheduling something.

1504
01:19:05,995 --> 01:19:07,230
What's that website?

1505
01:19:07,230 --> 01:19:08,650
Online is, online
scheduling is--

1506
01:19:08,650 --> 01:19:09,150
PROFESSOR: Doodle.

1507
01:19:09,150 --> 01:19:10,650
SAMAN AMARASINGHE: Doodle,
Doodle or something like that,

1508
01:19:10,650 --> 01:19:14,900
and get their times and then
they'll work with us to figure

1509
01:19:14,900 --> 01:19:17,910
out the place to meet, and then
they can send it out.

1510
01:19:17,910 --> 01:19:22,810
One thing we will have to do
is, between four students,

1511
01:19:22,810 --> 01:19:26,240
because every project we are
chaining the pairings, so

1512
01:19:26,240 --> 01:19:29,200
sometimes we might end up in a
way that, two of your students

1513
01:19:29,200 --> 01:19:32,170
are paired together, and then
we will tell you don't put

1514
01:19:32,170 --> 01:19:34,100
them together in the same group,
you'll basically have

1515
01:19:34,100 --> 01:19:36,010
to mix them in the other way.

1516
01:19:36,010 --> 01:19:38,860
If they are not in any kind
of a pairing, then you can

1517
01:19:38,860 --> 01:19:40,870
organize the four in
any way you want.

1518
01:19:43,610 --> 01:19:45,920
PROFESSOR: Actually I don't even
want of the four of them,

1519
01:19:45,920 --> 01:19:47,710
I don't even want us pairing.

1520
01:19:47,710 --> 01:19:48,630
That shouldn't be.

1521
01:19:48,630 --> 01:19:50,470
But we'll see what happens.

1522
01:19:50,470 --> 01:19:52,650
Barry?

1523
01:19:52,650 --> 01:19:56,756
AUDIENCE: Last year of course
was in classroom downstairs

1524
01:19:56,756 --> 01:20:00,018
and I just met them just
outside the classroom.

1525
01:20:00,018 --> 01:20:01,220
There's plenty of
little space.

1526
01:20:01,220 --> 01:20:03,450
PROFESSOR: Also the first floor
of STATA, I mean we've

1527
01:20:03,450 --> 01:20:05,090
had a lot of people just
using the first

1528
01:20:05,090 --> 01:20:06,820
floor of this building.

1529
01:20:06,820 --> 01:20:12,140
There's lots of cafe and place
there, and so forth, to sit

1530
01:20:12,140 --> 01:20:17,130
there, get a coffee,
and so forth.

1531
01:20:17,130 --> 01:20:19,330
So some people just did
something that informally,

1532
01:20:19,330 --> 01:20:22,960
other people wanted a more quiet
private place to talk.

1533
01:20:22,960 --> 01:20:28,460
And I think that we'll help the
students facilitate that.

1534
01:20:28,460 --> 01:20:31,340
SAMAN AMARASINGHE: And the key
thing is, especially if any

1535
01:20:31,340 --> 01:20:34,150
students are flaking out, for
example, doesn't answer your

1536
01:20:34,150 --> 01:20:37,590
email, or missed the meeting,
or something like that, or

1537
01:20:37,590 --> 01:20:38,600
late to the meeting,
let us know.

1538
01:20:38,600 --> 01:20:41,260
Because that's part of their
grade, even though you're not

1539
01:20:41,260 --> 01:20:46,420
grading them, if they are not
participating in working with

1540
01:20:46,420 --> 01:20:48,380
you guys, they will get
points deducted.

1541
01:20:48,380 --> 01:20:50,270
So we really want to know that,
and we have tried to

1542
01:20:50,270 --> 01:20:53,440
emphasize that they have to act,
and actually do it right.

1543
01:20:53,440 --> 01:20:56,320
So we really need to know that,
if the students are not

1544
01:20:56,320 --> 01:20:59,120
actually cooperating
with you guys.

1545
01:20:59,120 --> 01:21:02,775
PROFESSOR: So I hope that this
year will have a better--

1546
01:21:05,890 --> 01:21:09,380
So the vast majority of people
last year had no trouble, but

1547
01:21:09,380 --> 01:21:15,010
we did have a couple of people
for whom it was one or two

1548
01:21:15,010 --> 01:21:20,780
students who just made life a
little bit miserable for their

1549
01:21:20,780 --> 01:21:25,490
master, and so hopefully we'll
provide a few more incentives

1550
01:21:25,490 --> 01:21:28,670
this year to avoid
that situation.

1551
01:21:28,670 --> 01:21:33,110
But they're students
and so they--

1552
01:21:33,110 --> 01:21:35,700
AUDIENCE: When do we find
out which students

1553
01:21:35,700 --> 01:21:37,748
are assigned to us?

1554
01:21:37,748 --> 01:21:39,212
SAMAN AMARASINGHE: Probably
the next two days.

1555
01:21:42,628 --> 01:21:46,532
OK, and then who's responsible
for contacting whom?

1556
01:21:49,340 --> 01:21:50,144
That's a good question.

1557
01:21:50,144 --> 01:21:51,265
Who should we contact?

1558
01:21:51,265 --> 01:21:53,120
PROFESSOR: We decided that,
didn't we, at the meeting?

1559
01:21:53,120 --> 01:21:54,370
What did we decide?

1560
01:21:57,274 --> 01:21:58,556
AUDIENCE: This is what happens
when you don't

1561
01:21:58,556 --> 01:22:01,230
write things down.

1562
01:22:01,230 --> 01:22:02,640
SAMAN AMARASINGHE: You have
to cover the old stuff.

1563
01:22:09,530 --> 01:22:11,450
PROFESSOR: Let's see, so last
time I think we had it that

1564
01:22:11,450 --> 01:22:14,930
the students contacted the
mentor, and then--

1565
01:22:14,930 --> 01:22:17,090
SAMAN AMARASINGHE: What we will
do is we will set up,

1566
01:22:17,090 --> 01:22:19,820
we'll send the intro email to
everybody, we'll send the

1567
01:22:19,820 --> 01:22:22,860
intro email to the mentor, Cc
the student then saying I am

1568
01:22:22,860 --> 01:22:24,780
introducing you to each other.

1569
01:22:24,780 --> 01:22:27,880
And then one thing you can do
is immediately reply and, if

1570
01:22:27,880 --> 01:22:30,300
you have Peter Doodle Paul,
or something like that.

1571
01:22:30,300 --> 01:22:32,515
And then say, OK, look, do
you know your students?

1572
01:22:32,515 --> 01:22:34,570
So you can reply to that and
hopefully they will reply

1573
01:22:34,570 --> 01:22:36,170
back, and proceed.

1574
01:22:36,170 --> 01:22:38,865
So when we send you the names
you will also see the emails

1575
01:22:38,865 --> 01:22:39,120
of students.

1576
01:22:39,120 --> 01:22:40,755
PROFESSOR: Are people familiar
with doodle?

1577
01:22:40,755 --> 01:22:43,390
Anybody not familiar
with doodle?

1578
01:22:43,390 --> 01:22:47,850
So doodle is a website where
you can basically enter a

1579
01:22:47,850 --> 01:22:53,180
whole bunch of times, and then
people enter their names and

1580
01:22:53,180 --> 01:22:57,190
mark off which times they
can make things.

1581
01:22:57,190 --> 01:22:58,460
It's a poll source.

1582
01:22:58,460 --> 01:23:00,074
SAMAN AMARASINGHE: Don't do what
I did the last time, I

1583
01:23:00,074 --> 01:23:03,960
marked off all the times that I
cannot participate, so I was

1584
01:23:03,960 --> 01:23:05,200
basically the exact opposite.

1585
01:23:05,200 --> 01:23:09,310
PROFESSOR: It's green and red,
is what the colors they use.

1586
01:23:09,310 --> 01:23:12,615
So green means you can make it,
and red means you can't.

1587
01:23:12,615 --> 01:23:15,550
So, anyway you don't have to use
that facility, but it is a

1588
01:23:15,550 --> 01:23:16,810
convenient one to use.

1589
01:23:19,702 --> 01:23:23,360
AUDIENCE: Can we expect students
to be dropping?

1590
01:23:23,360 --> 01:23:24,470
SAMAN AMARASINGHE: There will
be people dropping.

1591
01:23:24,470 --> 01:23:25,740
They just started.

1592
01:23:28,820 --> 01:23:32,470
This is also a group project
and at 2:00 AM we got mails

1593
01:23:32,470 --> 01:23:34,910
saying OK, I'm dropping the
class, and we had to scramble

1594
01:23:34,910 --> 01:23:36,840
trying to add a 3:00 AM
to create another

1595
01:23:36,840 --> 01:23:39,180
group, and so, Yeah.

1596
01:23:39,180 --> 01:23:41,480
AUDIENCE: You shouldn't
take dropping as a

1597
01:23:41,480 --> 01:23:44,603
reflection on our end.

1598
01:23:44,603 --> 01:23:46,580
People drop out.

1599
01:23:46,580 --> 01:23:47,790
SAMAN AMARASINGHE: You
have to know that.

1600
01:23:47,790 --> 01:23:49,040
PROFESSOR: You can
if you want.

1601
01:23:54,136 --> 01:23:56,620
AUDIENCE: I had like
three people drop

1602
01:23:56,620 --> 01:23:59,314
PROFESSOR: No, that
tends to be more--

1603
01:23:59,314 --> 01:24:02,116
AUDIENCE: I had one student,
it was awesome.

1604
01:24:02,116 --> 01:24:04,460
So easy.

1605
01:24:04,460 --> 01:24:05,040
PROFESSOR: Yeah.

1606
01:24:05,040 --> 01:24:07,300
AUDIENCE: To get an idea of the
mindset the students are

1607
01:24:07,300 --> 01:24:12,258
going to be in this sort of a
really tough 6-170 type thing,

1608
01:24:12,258 --> 01:24:14,090
or is this one of the
easier classes.

1609
01:24:14,090 --> 01:24:15,570
PROFESSOR: No this is
a challenging class.

1610
01:24:15,570 --> 01:24:18,210
SAMAN AMARASINGHE: So
you take 6-170 that

1611
01:24:18,210 --> 01:24:19,490
has about four projects.

1612
01:24:19,490 --> 01:24:24,032
We doubled the number of
turn-ins because each project

1613
01:24:24,032 --> 01:24:26,540
has beta and a final, and
some projects has

1614
01:24:26,540 --> 01:24:27,680
two turn-ins in there.

1615
01:24:27,680 --> 01:24:31,250
So basically, they have all
their big projects going on,

1616
01:24:31,250 --> 01:24:34,145
because they are doing the
new project and they have

1617
01:24:34,145 --> 01:24:36,045
submitted final on the
previous project.

1618
01:24:36,045 --> 01:24:39,640
And they're already completed
project zero that was--

1619
01:24:39,640 --> 01:24:41,901
PROFESSOR: Just like
real life huh?

1620
01:24:41,901 --> 01:24:43,769
SAMAN AMARASINGHE: We gave
them project zero.

1621
01:24:43,769 --> 01:24:48,517
That was built to to get used to
the system and we can help

1622
01:24:48,517 --> 01:24:51,120
them with the class, they
have to finish this one.

1623
01:24:51,120 --> 01:24:54,585
So this class just screams
excess very, very--

1624
01:24:54,585 --> 01:24:59,150
PROFESSOR: Yeah, and of course
they're students, some of them

1625
01:24:59,150 --> 01:25:02,250
have learned you put off things
to the end, and haven't

1626
01:25:02,250 --> 01:25:07,195
learned the lessons of
well not always.

1627
01:25:10,470 --> 01:25:16,600
So as I said, as a group they're
relatively immature

1628
01:25:16,600 --> 01:25:19,420
when it comes to some of these
things, but there's a large

1629
01:25:19,420 --> 01:25:23,670
fraction of them who are
incredibly mature about these

1630
01:25:23,670 --> 01:25:24,430
kinds of things.

1631
01:25:24,430 --> 01:25:31,590
So our job is as lecturers in
the class is to make it so

1632
01:25:31,590 --> 01:25:35,180
that the students
who start work

1633
01:25:35,180 --> 01:25:37,360
early don't get penalized.

1634
01:25:37,360 --> 01:25:39,970
And that's probably the hardest
thing in the software

1635
01:25:39,970 --> 01:25:43,840
related class because, the
classic thing is that they

1636
01:25:43,840 --> 01:25:48,390
want to get started, they
find all the bugs right?

1637
01:25:48,390 --> 01:25:50,410
And they waste their time doing
it, and if you do it

1638
01:25:50,410 --> 01:25:53,900
later, then the TAs have worked
all the bugs out.

1639
01:25:53,900 --> 01:25:59,460
So one of our challenges is to
make it so that students who

1640
01:25:59,460 --> 01:26:05,090
start early are rewarded by
being able to have more time

1641
01:26:05,090 --> 01:26:06,350
not wasting their time.

1642
01:26:06,350 --> 01:26:08,440
SAMAN AMARASINGHE: And today was
the day that they turn in

1643
01:26:08,440 --> 01:26:11,530
the project and by looking at
the class, you realize they

1644
01:26:11,530 --> 01:26:13,810
haven't gone to sleep, and I
asked and most people haven't

1645
01:26:13,810 --> 01:26:15,290
slept in about 30 hours.

1646
01:26:15,290 --> 01:26:17,970
They have been up entire
last night and an email

1647
01:26:17,970 --> 01:26:20,390
conversation when I went
to sleep there was

1648
01:26:20,390 --> 01:26:21,360
an email train going.

1649
01:26:21,360 --> 01:26:22,740
Every five minutes,
something pop up.

1650
01:26:22,740 --> 01:26:26,200
When I woke up, the train was
still going, and amazingly,

1651
01:26:26,200 --> 01:26:29,317
there were a couple of TAs up
and answering all through the

1652
01:26:29,317 --> 01:26:31,600
night, and that kept
continuing.

1653
01:26:31,600 --> 01:26:36,200
So these kids they can be flaky
sometimes, but they're

1654
01:26:36,200 --> 01:26:37,280
amazingly hard working.

1655
01:26:37,280 --> 01:26:38,450
And this is only one class
they're taking.

1656
01:26:38,450 --> 01:26:41,630
They might be taking four
classes like that.

1657
01:26:41,630 --> 01:26:44,730
And I have seen people
scheduling their schedule as

1658
01:26:44,730 --> 01:26:47,510
by hour, scheduling and they
say, OK, look I can do the

1659
01:26:47,510 --> 01:26:49,680
problems set or I have
one hour of sleep.

1660
01:26:49,680 --> 01:26:52,580
And a lot of times that's
their thing, and then

1661
01:26:52,580 --> 01:26:55,180
sometimes they triage.

1662
01:26:55,180 --> 01:26:58,340
That's why sometimes they miss
classes, they realize, OK, I

1663
01:26:58,340 --> 01:27:02,490
can do the problem set, I can
sleep, I came do that.

1664
01:27:02,490 --> 01:27:05,600
So I think these kids
work amazingly hard.

1665
01:27:05,600 --> 01:27:09,500
PROFESSOR: I do think it's
helpful to also counsel them

1666
01:27:09,500 --> 01:27:13,570
on, hey, you can't do everything
on a death march.

1667
01:27:13,570 --> 01:27:17,660
You got to learn at some point
what you're capable of, and

1668
01:27:17,660 --> 01:27:21,390
manage your own time resources
and so forth.

1669
01:27:21,390 --> 01:27:25,640
Because the joke at
MIT is, classes,

1670
01:27:25,640 --> 01:27:27,670
friends, sleep, pick two.

1671
01:27:31,260 --> 01:27:33,920
The other thing, let me just
say, is that despite the

1672
01:27:33,920 --> 01:27:39,430
obvious sleep deprivation we
saw in the class today the

1673
01:27:39,430 --> 01:27:43,150
number of students who came up
after class so charged about

1674
01:27:43,150 --> 01:27:49,010
working on this first project
was really quite amazing.

1675
01:27:49,010 --> 01:27:50,570
They were all very,
very excited.

1676
01:27:50,570 --> 01:27:54,030
And very excited we also gave
them the initial feedback on

1677
01:27:54,030 --> 01:27:57,000
the performance, and you could
see, there's one group of

1678
01:27:57,000 --> 01:27:59,480
students who clearly got it, and
then there's another tier

1679
01:27:59,480 --> 01:28:03,670
of students who didn't get it
quite this much, and then

1680
01:28:03,670 --> 01:28:07,120
there's the ones who their code
has errors and stuff.

1681
01:28:10,280 --> 01:28:14,110
There's no doubt that there are
a lot of students who are

1682
01:28:14,110 --> 01:28:15,630
very charged about this.

1683
01:28:15,630 --> 01:28:18,270
This is a fun class but
it's a hard class.

1684
01:28:21,020 --> 01:28:23,040
SAMAN AMARASINGHE: I think
you'll find this is true.

1685
01:28:23,040 --> 01:28:26,240
They will be, probably tired,
but they will be soaking up

1686
01:28:26,240 --> 01:28:29,280
this information like a
sieve, and sometimes

1687
01:28:29,280 --> 01:28:32,590
I found last year's--

1688
01:28:32,590 --> 01:28:36,080
After the looking at the first
set of code, some of those the

1689
01:28:36,080 --> 01:28:38,200
masters were really upset.

1690
01:28:38,200 --> 01:28:40,820
How can you teach you guys,
these guys write this kind of

1691
01:28:40,820 --> 01:28:43,950
bad code, but when they realized
after they said

1692
01:28:43,950 --> 01:28:45,790
something, this is getting
into their heads.

1693
01:28:45,790 --> 01:28:47,900
I mean, they're improving
they're actually changing.

1694
01:28:47,900 --> 01:28:49,920
These guys are very smart,
and they're looking

1695
01:28:49,920 --> 01:28:51,470
for you guys for--

1696
01:28:51,470 --> 01:28:54,790
They're basically sponge,
really empty sponge.

1697
01:28:54,790 --> 01:28:59,220
They're going absorb a
lot in this class.

1698
01:28:59,220 --> 01:29:02,610
PROFESSOR: I have a 2 and 1/2
year old at home, and it's

1699
01:29:02,610 --> 01:29:07,545
amazing what the progress is
she's made in six months.

1700
01:29:07,545 --> 01:29:12,910
She talking now in complete
sentences, and so forth, it's

1701
01:29:12,910 --> 01:29:14,990
just really amazing how how
she does it, and these

1702
01:29:14,990 --> 01:29:16,630
students are like that.

1703
01:29:16,630 --> 01:29:19,410
They start out and you say, oh
my God, they have no skills

1704
01:29:19,410 --> 01:29:19,730
whatsoever.

1705
01:29:19,730 --> 01:29:24,280
By the end of the term the
progress that they've made is

1706
01:29:24,280 --> 01:29:26,120
really astounding.

1707
01:29:26,120 --> 01:29:29,080
You just say, gee if you could
just keep on that trajectory

1708
01:29:29,080 --> 01:29:31,860
your whole life.

1709
01:29:31,860 --> 01:29:34,240
But really, they really are very
smart, and they come up

1710
01:29:34,240 --> 01:29:38,230
to speed very, very fast,
especially given good

1711
01:29:38,230 --> 01:29:38,660
counseling.

1712
01:29:38,660 --> 01:29:41,180
The main thing that they need
right now is just the

1713
01:29:41,180 --> 01:29:43,880
attention so somebody actually
can look at their code and

1714
01:29:43,880 --> 01:29:48,640
say, you know you did it like
this it would be better code.

1715
01:29:54,760 --> 01:29:57,740
Any other questions or issues?

1716
01:29:57,740 --> 01:29:58,950
This is lots of fun.

1717
01:29:58,950 --> 01:30:01,960
If you run into any troubles,
we're right here,

1718
01:30:01,960 --> 01:30:03,970
just send us email.

1719
01:30:03,970 --> 01:30:12,390
And as I say they're young and
immature, but then you get to

1720
01:30:12,390 --> 01:30:16,840
see them grow, of course some of
them will flake out on you,

1721
01:30:16,840 --> 01:30:22,780
but the vast majority, you'll
see, are really very dedicated

1722
01:30:22,780 --> 01:30:23,520
and well meaning.

1723
01:30:23,520 --> 01:30:26,380
They really want to do a good
job in the class, and really,

1724
01:30:26,380 --> 01:30:28,240
really find the class
very exciting.

1725
01:30:28,240 --> 01:30:34,440
Our numbers, in fact, almost
doubled for last year.

1726
01:30:34,440 --> 01:30:38,990
So the reputation got around
that this was a

1727
01:30:38,990 --> 01:30:40,460
good class to be doing.

1728
01:30:40,460 --> 01:30:44,570
And the other thing is, right
now what I really like about

1729
01:30:44,570 --> 01:30:47,450
the class, the students right
now compared with

1730
01:30:47,450 --> 01:30:49,260
say 10 years ago.

1731
01:30:49,260 --> 01:30:52,940
So 10 years ago we had the
Internet boom, and there were

1732
01:30:52,940 --> 01:30:56,960
all kinds of students taking
computer science because they

1733
01:30:56,960 --> 01:31:01,140
thought it was a ticket to
fortune and so forth.

1734
01:31:01,140 --> 01:31:11,790
And now we're back to what it
was pre-2000, 1998, whatever.

1735
01:31:11,790 --> 01:31:14,040
Where the vast majority of
students who are taking the

1736
01:31:14,040 --> 01:31:16,840
class really enjoy
engineering.

1737
01:31:16,840 --> 01:31:18,270
They really enjoy
the software.

1738
01:31:18,270 --> 01:31:19,390
They really enjoy
the engineering.

1739
01:31:19,390 --> 01:31:23,690
The fact that you end up with
a pretty good job and

1740
01:31:23,690 --> 01:31:26,650
opportunity sometimes to do
entrepreneurship, and

1741
01:31:26,650 --> 01:31:31,320
opportunity to explore things,
it's sort of like, oh that's a

1742
01:31:31,320 --> 01:31:32,090
fringe benefit.

1743
01:31:32,090 --> 01:31:35,030
But what they're really after
is just the intellectual

1744
01:31:35,030 --> 01:31:36,110
excitement and so forth.

1745
01:31:36,110 --> 01:31:40,070
So it's really quite fun to
work with the students and

1746
01:31:40,070 --> 01:31:42,810
quite rewarding.

1747
01:31:42,810 --> 01:31:45,820
Really very nice type of class
to have right now, where the

1748
01:31:45,820 --> 01:31:48,140
students taking it because
they're actually interested in

1749
01:31:48,140 --> 01:31:51,990
the material, not because it
buys them a bread ticket, meal

1750
01:31:51,990 --> 01:31:54,510
ticket, whatever.

1751
01:31:54,510 --> 01:31:55,020
Yeah, question?

1752
01:31:55,020 --> 01:31:57,280
AUDIENCE: The standard, is the
coding standard in the

1753
01:31:57,280 --> 01:32:02,740
reference, the standard is to
consider for them provided?

1754
01:32:02,740 --> 01:32:05,790
SAMAN AMARASINGHE: I don't
think we have set up a

1755
01:32:05,790 --> 01:32:07,280
standard, per se.

1756
01:32:07,280 --> 01:32:09,660
What we want them
to do is kind of

1757
01:32:09,660 --> 01:32:11,640
create their own style.

1758
01:32:11,640 --> 01:32:16,240
It's like in a writing class,
you don't give them a standard

1759
01:32:16,240 --> 01:32:18,615
writing guideline is to follow
this one, you don't constrain

1760
01:32:18,615 --> 01:32:20,260
them to that.

1761
01:32:20,260 --> 01:32:24,980
We want to give them the
opportunity to grow into their

1762
01:32:24,980 --> 01:32:29,905
style, but kind of guide them,
so that they don't make the

1763
01:32:29,905 --> 01:32:31,155
classic mistakes.

1764
01:32:33,930 --> 01:32:36,350
That's why we need you guys, I
mean, if there's a standard,

1765
01:32:36,350 --> 01:32:38,490
we can come up with a standard,
create a script to

1766
01:32:38,490 --> 01:32:40,790
actually check the standard, and
then say, OK, thou shall

1767
01:32:40,790 --> 01:32:41,960
follow the standard.

1768
01:32:41,960 --> 01:32:43,880
And you can do that and
everybody will hate it.

1769
01:32:46,410 --> 01:32:47,710
You can't make that
bad happen.

1770
01:32:47,710 --> 01:32:50,350
One thing you want to do is
make them lifelong good

1771
01:32:50,350 --> 01:32:53,250
coders, not something they
realize OK, I need to do this

1772
01:32:53,250 --> 01:32:55,360
to get this grade, and I'm going
to abandon everything

1773
01:32:55,360 --> 01:32:57,740
and convince myself never
to that again.

1774
01:32:57,740 --> 01:33:00,400
And we have had sometimes, like
when we needed all this

1775
01:33:00,400 --> 01:33:00,900
software engineering.

1776
01:33:00,900 --> 01:33:03,650
We went through things like
thou shall write all the

1777
01:33:03,650 --> 01:33:06,330
preconditions and
postconditions, and everything

1778
01:33:06,330 --> 01:33:06,910
will be graded.

1779
01:33:06,910 --> 01:33:11,700
And people did it, but half of
them got into them and said

1780
01:33:11,700 --> 01:33:12,380
this is good things.

1781
01:33:12,380 --> 01:33:14,340
Other half, they didn't realize
why they're doing it,

1782
01:33:14,340 --> 01:33:15,480
they just hated it.

1783
01:33:15,480 --> 01:33:19,200
And I don't think they
left assuming I would

1784
01:33:19,200 --> 01:33:20,120
never do this again.

1785
01:33:20,120 --> 01:33:22,270
So the key thing here is,
we don't want force

1786
01:33:22,270 --> 01:33:23,410
something on to them.

1787
01:33:23,410 --> 01:33:25,830
We want them to come through a
natural process, and I think a

1788
01:33:25,830 --> 01:33:28,110
lot of them, can, when they
understand what they're doing,

1789
01:33:28,110 --> 01:33:30,790
they'll develop a really
good kind of practice.

1790
01:33:30,790 --> 01:33:35,180
PROFESSOR: It's also the case, I
think, that coding standards

1791
01:33:35,180 --> 01:33:38,570
vary culturally from place to
place, and the what people

1792
01:33:38,570 --> 01:33:41,250
expect in one place is different
from what thing.

1793
01:33:41,250 --> 01:33:45,490
So being too prescriptive means,
as Saman is saying,

1794
01:33:45,490 --> 01:33:50,730
that it becomes a grammatical
thing, rather than is this

1795
01:33:50,730 --> 01:33:51,970
code organized.

1796
01:33:51,970 --> 01:33:54,660
The real thing, coding standards
are very important,

1797
01:33:54,660 --> 01:34:00,230
especially in large software
organizations of course, so

1798
01:34:00,230 --> 01:34:03,340
that everybody can tell what's
going on in any particular

1799
01:34:03,340 --> 01:34:05,750
piece of code without having
been the author.

1800
01:34:05,750 --> 01:34:09,100
But in this kind of thing where
we have something that's

1801
01:34:09,100 --> 01:34:11,830
relatively small, what we're
mostly interested in is the

1802
01:34:11,830 --> 01:34:17,940
organizational aspects of coding
style, as opposed to

1803
01:34:17,940 --> 01:34:20,950
the grammatical ones.

1804
01:34:20,950 --> 01:34:23,650
SAMAN AMARASINGHE: So also don't
impose your standard and

1805
01:34:23,650 --> 01:34:26,500
say, my company this is what we
do, I want to follow that.

1806
01:34:26,500 --> 01:34:29,740
Just figure out and kind of
guide them towards something

1807
01:34:29,740 --> 01:34:33,260
while they're maturing, and
try to make it better.

1808
01:34:33,260 --> 01:34:33,820
That's the thing.

1809
01:34:33,820 --> 01:34:37,660
That's why you cannot have
a cookie-cutter model.

1810
01:34:37,660 --> 01:34:39,550
PROFESSOR: And why it's good
to have senior software

1811
01:34:39,550 --> 01:34:47,300
engineers who understand what's
really important, as

1812
01:34:47,300 --> 01:34:55,900
opposed to what might be
required in any particular

1813
01:34:55,900 --> 01:34:58,780
individual situation.

1814
01:34:58,780 --> 01:35:01,245
SAMAN AMARASINGHE: One other
topic I want to add is

1815
01:35:01,245 --> 01:35:04,430
sometimes when you have two
students, there might be a

1816
01:35:04,430 --> 01:35:07,750
case that one person might be
very talkative and dominating,

1817
01:35:07,750 --> 01:35:10,250
and one person might be just a
listener, and so you have to

1818
01:35:10,250 --> 01:35:14,360
keep an eye on that and make
sure that you give the other

1819
01:35:14,360 --> 01:35:17,430
person opportunities to talk,
and because it might

1820
01:35:17,430 --> 01:35:19,050
be just like that.

1821
01:35:19,050 --> 01:35:21,540
Encouragement and stuff like
that, so make sure that you

1822
01:35:21,540 --> 01:35:23,940
get both of them to talk.

1823
01:35:23,940 --> 01:35:25,980
And also the are supposed to be

1824
01:35:25,980 --> 01:35:27,150
responsible for all the code.

1825
01:35:27,150 --> 01:35:29,850
You should not let them get away
by saying, oh my partner

1826
01:35:29,850 --> 01:35:31,530
wrote it, so I don't
understand.

1827
01:35:31,530 --> 01:35:33,700
So that's not a good answer.

1828
01:35:33,700 --> 01:35:36,980
So get them to actually go
through that, and if they

1829
01:35:36,980 --> 01:35:39,970
don't come prepared tell them
that, and you can give them

1830
01:35:39,970 --> 01:35:41,930
some feedback, as a next
time can you please

1831
01:35:41,930 --> 01:35:44,260
do, this and this.

1832
01:35:44,260 --> 01:35:46,640
Because they also don't know
what to expect, and we give

1833
01:35:46,640 --> 01:35:49,610
them a little bit of guideline,
but it'll be good,

1834
01:35:49,610 --> 01:35:51,870
also for you, the first time
around, if you find some

1835
01:35:51,870 --> 01:35:56,000
mistakes also for the next code
review you can encourage

1836
01:35:56,000 --> 01:35:58,970
them what to do, how to prepare
and what to do.

1837
01:35:58,970 --> 01:36:01,470
Don't give them too much work,
because we're already giving

1838
01:36:01,470 --> 01:36:02,140
them enough work.

1839
01:36:02,140 --> 01:36:05,750
Don't ask them to write extra
documentation, but you can say

1840
01:36:05,750 --> 01:36:09,040
it would have been nice if you
had this level of preparation,

1841
01:36:09,040 --> 01:36:11,990
if you could have explained to
me, or given me a summary, or

1842
01:36:11,990 --> 01:36:12,810
something like that.

1843
01:36:12,810 --> 01:36:16,100
So something like that is
something you can expect.

1844
01:36:16,100 --> 01:36:19,580
And the other thing is if you
had to figure out how we want

1845
01:36:19,580 --> 01:36:20,280
to do code review.

1846
01:36:20,280 --> 01:36:23,090
So, for example, you might want
to bring your laptop, or

1847
01:36:23,090 --> 01:36:26,540
ask them to bring a laptop in
there, if you want each other

1848
01:36:26,540 --> 01:36:29,000
to look at the code on the
computer, so ask them to bring

1849
01:36:29,000 --> 01:36:30,590
the laptops or something.

1850
01:36:30,590 --> 01:36:34,830
So think about the logistics
of how you're going to do

1851
01:36:34,830 --> 01:36:37,050
that, and that'll be useful.

1852
01:36:37,050 --> 01:36:39,290
PROFESSOR: And I think any other
sort of expectations you

1853
01:36:39,290 --> 01:36:45,530
have, in your email to them
the first time say, here's

1854
01:36:45,530 --> 01:36:46,610
what I'd like you.

1855
01:36:46,610 --> 01:36:48,760
I think it's helpful to say I'd
like you to come prepared

1856
01:36:48,760 --> 01:36:53,120
to give me a five minute update
on how you did each of

1857
01:36:53,120 --> 01:36:54,760
the problems, for example.

1858
01:36:54,760 --> 01:36:57,310
We will be telling them that,
but to have it come directly

1859
01:36:57,310 --> 01:37:00,320
from you means--

1860
01:37:00,320 --> 01:37:03,550
The difference if I say go do
this to that person, versus

1861
01:37:03,550 --> 01:37:08,870
you're coming to me
and expecting it.

1862
01:37:08,870 --> 01:37:10,120
Good.

1863
01:37:11,700 --> 01:37:17,140
So, I want to once again, I
can't thank you folks enough

1864
01:37:17,140 --> 01:37:20,360
for being willing to
give your time.

1865
01:37:20,360 --> 01:37:27,390
Time is the stuff life is made
out of, so I really appreciate

1866
01:37:27,390 --> 01:37:31,870
your willingness to volunteer
your time for these students,

1867
01:37:31,870 --> 01:37:37,040
and I really think you have a
dramatically meaningful impact

1868
01:37:37,040 --> 01:37:38,290
on the students.

1869
01:37:40,610 --> 01:37:44,690
The students may or may not
fully appreciate that, OK, but

1870
01:37:44,690 --> 01:37:48,990
Saman and I really appreciate
that, and we will make sure

1871
01:37:48,990 --> 01:37:52,012
the students appreciate it.

1872
01:37:52,012 --> 01:37:52,505
AUDIENCE: Yeah.

1873
01:37:52,505 --> 01:37:53,491
I just have one.

1874
01:37:53,491 --> 01:37:56,942
What what are the guidelines for
a contact outside of the

1875
01:37:56,942 --> 01:37:58,421
code reviews with
the students.

1876
01:37:58,421 --> 01:38:03,130
I mean are they, can we have
them email us with questions

1877
01:38:03,130 --> 01:38:06,460
about the process and just
kind of general guidance

1878
01:38:06,460 --> 01:38:08,990
PROFESSOR: It's your level of
tolerance we don't want you to

1879
01:38:08,990 --> 01:38:12,640
have to commit more than about
20 hours across the term,

1880
01:38:12,640 --> 01:38:14,690
because then it becomes
onerous.

1881
01:38:14,690 --> 01:38:20,520
But if you're willing I think
it's completely open ended, in

1882
01:38:20,520 --> 01:38:22,320
terms of how much else.

1883
01:38:29,110 --> 01:38:31,560
I mean it's one thing if you go
into solving their problems

1884
01:38:31,560 --> 01:38:34,810
for them, that we don't want you
doing, but when it comes

1885
01:38:34,810 --> 01:38:47,990
to, especially the quality, and
non-metrical aspects of

1886
01:38:47,990 --> 01:38:51,820
programming, the more you can
give them the better, OK?

1887
01:38:51,820 --> 01:38:55,780
Because it's only making them
be better programmers.

1888
01:38:55,780 --> 01:38:58,430
And I think the fact that there
may be some unevenness

1889
01:38:58,430 --> 01:39:01,530
in that across the masters
is irrelevant.

1890
01:39:01,530 --> 01:39:06,100
Really, I do not want to hold
back some students from

1891
01:39:06,100 --> 01:39:09,140
getting good mentorship because
somebody else is not

1892
01:39:09,140 --> 01:39:13,870
getting the same level of
attention, et cetera.

1893
01:39:13,870 --> 01:39:17,560
But really, no expectation
there, on our part, to do more

1894
01:39:17,560 --> 01:39:21,760
than the code reviews
themselves.

1895
01:39:21,760 --> 01:39:22,760
SAMAN AMARASINGHE: So, that said
I want to make sure that

1896
01:39:22,760 --> 01:39:24,990
you aren't answering their
question, at some point I

1897
01:39:24,990 --> 01:39:28,330
don't want to be a
crutch for them.

1898
01:39:28,330 --> 01:39:32,100
For example, if they say, OK,
before prebeta, they say OK,

1899
01:39:32,100 --> 01:39:35,030
this is my next problem, can you
on a little bit, I didn't

1900
01:39:35,030 --> 01:39:35,810
understand.

1901
01:39:35,810 --> 01:39:39,060
If you have that, so they're
trying to get too much into

1902
01:39:39,060 --> 01:39:42,830
that level, kind of making you
their programmer, or something

1903
01:39:42,830 --> 01:39:44,810
like that, just let us know.

1904
01:39:44,810 --> 01:39:47,610
A lot of these things, there
will be a lot of cases that

1905
01:39:47,610 --> 01:39:49,890
arise that we haven't
thought through.

1906
01:39:49,890 --> 01:39:52,280
The students are ingenious
enough they will find a lot of

1907
01:39:52,280 --> 01:39:54,245
loopholes, a lot of kind of
interesting things that we

1908
01:39:54,245 --> 01:39:55,090
never thought through.

1909
01:39:55,090 --> 01:39:57,740
So if you find something that
you're not feeling comfortable

1910
01:39:57,740 --> 01:39:59,800
just send a mail and say
OK, take a look.

1911
01:39:59,800 --> 01:40:01,840
PROFESSOR: It really is, if
their questions are about

1912
01:40:01,840 --> 01:40:04,540
course content it's not
appropriate for you folks to

1913
01:40:04,540 --> 01:40:05,545
be dealing with, really.

1914
01:40:05,545 --> 01:40:08,380
OK, that's what our TAs are
for, and course staff.

1915
01:40:08,380 --> 01:40:17,770
If it's about coding style and
engineering practice, and even

1916
01:40:17,770 --> 01:40:20,760
time management, or anything
that's sort of the

1917
01:40:20,760 --> 01:40:27,130
non-technical aspects, but
things that have a strong

1918
01:40:27,130 --> 01:40:29,830
impact on technical, that yes.

1919
01:40:29,830 --> 01:40:31,510
Anything you can provide
there is great.

1920
01:40:31,510 --> 01:40:34,330
SAMAN AMARASINGHE: So if you
find anything that's outside

1921
01:40:34,330 --> 01:40:36,310
the norm of what we discussed
if you feel a little bit

1922
01:40:36,310 --> 01:40:37,620
uncomfortable, just
send email.

1923
01:40:37,620 --> 01:40:39,560
Send an email, and say,
hey, can I do this?

1924
01:40:39,560 --> 01:40:40,400
Is it OK, for me to do this?

1925
01:40:40,400 --> 01:40:43,480
And then we can always provide
guidance, so we are

1926
01:40:43,480 --> 01:40:43,690
responsible.

1927
01:40:43,690 --> 01:40:45,680
PROFESSOR: --do something and
say after the fact, oh, it

1928
01:40:45,680 --> 01:40:48,690
went past, let us know.

1929
01:40:48,690 --> 01:40:54,760
There's rarely anything you can
do on one shot basis that

1930
01:40:54,760 --> 01:40:59,070
is heinous or unrecoverable
from, or whatever, so.

1931
01:40:59,070 --> 01:40:59,840
SAMAN AMARASINGHE: It
is always good,

1932
01:40:59,840 --> 01:41:01,670
I mean that's why--

1933
01:41:01,670 --> 01:41:04,340
since we see everybody able to
and we have done these kind of

1934
01:41:04,340 --> 01:41:05,460
situation before.

1935
01:41:05,460 --> 01:41:07,270
We can just easily
tell you what.

1936
01:41:07,270 --> 01:41:12,350
PROFESSOR: But, mentor them,
for sure, mentor them.

1937
01:41:12,350 --> 01:41:14,270
SAMAN AMARASINGHE: I think a lot
of times, when you talk to

1938
01:41:14,270 --> 01:41:19,290
students last time they got a
lot more information out from

1939
01:41:19,290 --> 01:41:22,540
the masters, other than
just the coding style.

1940
01:41:22,540 --> 01:41:25,050
I mean, they talk about what is
it like to be an engineer

1941
01:41:25,050 --> 01:41:26,240
in a company, what
are the things?

1942
01:41:26,240 --> 01:41:27,710
And so they get a good feel.

1943
01:41:27,710 --> 01:41:30,200
I mean, some of them might
not have done a

1944
01:41:30,200 --> 01:41:31,560
internship in a company.

1945
01:41:31,560 --> 01:41:32,340
So they don't know.

1946
01:41:32,340 --> 01:41:36,490
I mean, they're just green, and
talking to you guys they

1947
01:41:36,490 --> 01:41:38,010
get a feel for what it's like.

1948
01:41:38,010 --> 01:41:40,940
And also from a non-marketing
situation too.

1949
01:41:40,940 --> 01:41:43,440
I mean you might have ulterior
motives to market your company

1950
01:41:43,440 --> 01:41:45,940
to them, and stuff, but this is
not that they're going into

1951
01:41:45,940 --> 01:41:47,080
a job interview.

1952
01:41:47,080 --> 01:41:48,630
So, for a lot of
them it's rare.

1953
01:41:48,630 --> 01:41:51,090
I mean they might not have
retinues of friends that they

1954
01:41:51,090 --> 01:41:53,160
can go and talk at that
kind of casual level.

1955
01:41:53,160 --> 01:41:55,250
Most of the time they're on
guard because they're on an

1956
01:41:55,250 --> 01:41:59,870
interview or they assume that
information coming to them

1957
01:41:59,870 --> 01:42:02,830
will be sugar-coated, and here
is a way that they can get--

1958
01:42:02,830 --> 01:42:05,160
I think it's very
good for them.

1959
01:42:05,160 --> 01:42:06,665
PROFESSOR: Eight minutes
over time.

1960
01:42:06,665 --> 01:42:08,070
SAMAN AMARASINGHE: OK,
I think we should.

1961
01:42:08,070 --> 01:42:12,650
PROFESSOR: So, any last
final comments?

1962
01:42:12,650 --> 01:42:15,190
Saman and I will hang around for
a few minutes, for anybody

1963
01:42:15,190 --> 01:42:17,350
wants to chat more one one.

1964
01:42:17,350 --> 01:42:24,620
And one and once again I thank
you for all the time that

1965
01:42:24,620 --> 01:42:28,420
you're planning to put into
the 6-172, thanks.

1966
01:42:28,420 --> 01:42:29,670
AUDIENCE: Thank you.