SPEAKER 1: All right, this is CS50, and this is week 11.

Before we begin today, I thought we'd make some changes in light

of the competition on the horizon.

First and foremost, this is perhaps in order.

And I was down the street just earlier, and I

got my shirt for the weekend, which I gather means 900.

So good luck this weekend.

And before we proceed further, a big thanks to the whole team, honestly,

that made this semester possible--

Natalie, in particular, who I'm sure you've

gotten to know over time, of course, Benedict with whom I

went to college some years ago.

You recall this picture from week 0, and then of course [? Stelios ?]

and [? Anusery ?] and the whole team of TAs and CAs here.

And, indeed, this is actually a pretty novel thing.

If you haven't quite realized it, especially

if you're first year, having undergraduate ULAs [CRASH] or tada.

[LAUGHS]

That's anticlimactic.

OK, so we will tend to this later.

So this is actually a pretty novel thing,

that there are undergraduates teaching assistants, that you guys can actually

teach your own classes, hold office hours, and more.

And this was actually initiated just a few years ago by way

of CS50's first class of TAs and CAs.

So here's a [INAUDIBLE] article from back in 2015.

In fact, this is the very first team of undergraduate CAs

who first TAed CS50 itself.

And in fact, this is now an opportunity that has extended beyond CS50 itself.

So if you're thinking about computer science or really any related field

and you might like to start teaching-- which frankly is by far the best

way to actually learn and absorb this kind of material--

realize that CS50 itself will soon start recruiting, and we and the whole team

would indeed love to have you on the team.

And even if you are among or were among those less comfortable,

keep in mind that's what we said in the first lecture still

holds true here on out.

What really matters ultimately in this class,

even if it might not quite feel like this-- it's just what?

Four hours after the quiz was due--

that what really matters in this course is not so much

where you end up relative to your classmates,

but where you end up relative to yourselves.

And that's something we have and will keep

in mind, especially when it comes time for final projects, grades, and beyond.

And in fact, these were the percentages broken down

in the very first lecture based on problem set zero of this year.

So those of you who have been feeling that you

are among those less comfortable realize that it's no longer by definition

the case.

Everyone's been upgraded to somewhere in between or among those

more comfortable, and realize this is perhaps

just the first such stepping stone.

So this has been a tradition of having undergrads TA the class for years

up in Cambridge.

And in fact, the team there put together with our production team

a little invitation for you to consider joining us here

in New Haven among our CAs and TAs for the coming year.

So allow me to dim the lights and have our team in Cambridge say hello.

[VIDEO PLAYBACK]

- I'm Elsiah.

- My name is Nenia.

- I'm Athena Braun.

- I'm a sophomore.

- I'm a senior.

- I'm a junior studying in computer science and linguistics.

- I'm concentrating in [? CSL. ?]

- CS50 is always just because it's changed my life.

It made me a computer science concentrator.

- I'm a TF for CS50.

- Course assistant.

- This is my second year TFing now.

- This is my third year being a teaching fellow for CS50.

- Becoming part of CF's staff helped empower me so so so much.

- I was a total beginner, never anticipated programming beyond CS50.

But here I am.

This is something I never thought I would do.

I think it's just been really exciting going from being a beginner

to being comfortable enough to TF this class.

- Everything that has come out of this has

helped me grow so much as a teacher, as a student.

- Also the culture and the environment of it is also pretty.

- I've definitely found a community of friends within the CS50 staff.

- Be prepared to have students who look up to you

and really appreciate the work that you're doing.

And just realize that you're not just a teaching fellow.

You're not just this person behind the whiteboard.

You're like a student who took this, too,

and can really level with other people in your section

and figure out what's going on and make it a good experience for them.

- I decided that I can get the best of both worlds.

I can get to teach about computer science.

And those are two are my passions.

- I just really love teaching computer science to beginners.

CS50 is where all that beginner energy is,

and it's where I can make a real impact on the students' careers in CS.

- It's amazing to see how much this course can do in just a semester

and how, from September until December, students learn so much

and gain so much experience and knowledge.

And watching that and working with them in that process

has always been really, really inspiring.

- It's been so so wonderful getting to see these people grow,

just like I did myself.

- One of the most rewarding things I've done here.

So that's why I keep coming back.

- Going to office hours and helping people out, it makes you feel good.

And it makes other people feel good as well.

- My name is Brian.

- I'm Thomas Lively.

- I'm Allison.

- I'm Maria.

And this is CS50.

[END PLAYBACK]

SPEAKER 1: So realize, here in New Haven and also in Cambridge,

we're fortunate to have quite a few resources,

both in terms of the place that we're in and the people that we're around.

And one of the focuses of CS50 for years now with its staff

has been on something called open courseware, whereby we've long

made the courses, videos, and problem sets and software freely available

to everyone around the world.

And just a couple of years, too, did we start

to focus, not just on students who wanted

to tune in in any country and any city, have we also started

focusing on teachers as well so that they needn't rely only on the textbooks

that their schools provide but too can get on the internet and tune into

and use in their own classrooms, adapting or adopting

this particular curriculum and tools for their own students.

And if curious, for instance, every red dot on this map

actually represents some cohort of high school students

and high school teachers teaching introductory [? CFs ?] via CF50AP

as it's called, and every one of the blue dots on the screen

represents a university with whom we've been collaborating in some form,

either formally with some of the faculty or less

formally with some of the student groups there.

And so if you're interests in education and in computer science

extend beyond, by all means consider applying,

not only to TA or SA the class, but to get involved

in these other outreach efforts creating curricula, working on tools,

and really making an impact.

In fact, the communities beyond Cambridge and New Haven

include Miami Dade in Florida.

This is Chile.

This is our team in London.

Here in Burma.

Here in Ukraine.

Here in Cairo.

Here in Bolivia and Nicaragua, and then lastly back home in Cambridge.

This was our very first cohort of high school teachers

who came to town in order to bring a little something back

to their own classrooms and teach and adapt as well there.

And in fact, just a few years ago, apropos

of the event on our own horizon, this was the very first CF50AP hackathon,

whereas instead of getting together at 7:00 PM To 7:00 AM,

we got together like 10 AM to 2 PM during the high school schedule.

And we had eight public and private high schools

in the New York City area come together to work on their own problems sets

and final projects and the like.

So again, if of interest, do you feel welcome to engage

with us and so many people around the world in that way.

So what have we actually done in the classroom and in the problem sets?

So at the end of the day, it's all about problem solving.

And hopefully, if you attended CF50 Puzzle Day

or certainly engaged in the problems over the past several weeks,

you realize that the goals of this class are not so much to teach you C per se,

and it doesn't really matter some of the finer

implementation details of a lot of the problem sets,

but how you went about solving those problems.

And we claimed early on that there is a methodology,

and there's techniques with which you can solve problems.

And indeed, we hope what you exit the course with is sort of an ability

now to recognize patterns and other problems you might encounter, not

just in CS, but in other fields too.

If curious as to how some of your classmates

perceived this year's problem sets, we took a look at the data

that you kindly provided in problems set eight.

This is a bar chart of what everyone thought of the problem set.

So purple is hate.

Blue is love.

So it's hate on top down to love on the bottom.

And so what you can see here is that love was kind of invariant,

though there was even more liking of problem sets 6 over here.

No one really hated problems set 1, which

is fantastic, with Mario and the likes.

So perhaps you're somewhere in that spectrum.

A little more telling was this.

How difficult were the problem sets?

And these numbers varied a lot more.

[? P ?] said 0 and 1 were very blue because blue is easy,

green meanwhile on the top would represent hard.

So there's definitely some fluctuation based

on expectations of the problem sets and which one were newer or in progress.

But problem set 5--

so misspellings, the spellcheckers-- it's probably pretty fair to say it's

pretty orange and a bunch of green, whereas pset

6 kind of went the other direction, where you had the ability

to port some of our programs from C to Python

and implement some document similarity.

When did you start problem sets?

More telling.

So [INAUDIBLE] called that they are released way over here on a Friday,

but the most common day seems to be Wednesday followed by Friday, followed

by Thursday.

Thankfully zero people said they started it the morning of it being due.

So that's a little something.

And then lastly, when did you watch lectures?

So it seems that Monday was the common case.

Some folks tuned in live on Friday or watched it on demand thereafter,

Saturday, Sunday being common.

And then there's perhaps correlation between the blue Sunday

and the blue Sunday for problem sets as well.

So just to give you a sense of your own patterns as well.

So where did we begin?

So you recalled that we came on up here some 12 weeks ago

and played this, IVs hardest game, which was a game written in Scratch

but was all about trying to solve some problem.

And we distilled this notion of problem solving really into this black box.

At the end of the day, all problem solving is is you've got some input--

and we happen to represent them in so many different ways, zeros

and ones, letters of the alphabet, colors and files, and web requests,

and more.

But at the end of the day, what you care about is the outputs.

And the secret sauce in the middle, we've kept calling what?

OK, you're wearing the I took CF50 shirt, so you better have an answer.

What's inside the box?

Grhythms, exactly.