DAVID MALAN: This is Sanders Theatre. This is where CS50's lectures are held. Thanks so much for coming to campus. Shall we start with introductions? I'm David. 

AMY: I'm Amy. I work on the web, and I live here in Cambridge. 

JACK: I'm Jack and I'm from Dublin, Ireland. I'm a junior in high school. 

DAVID MALAN: And what brings you here today in particular from so far away? 

JACK: Eh, for a visit of Boston. DAVID MALAN: OK. AMY: How has CS50 evolved as you've been teaching it? DAVID MALAN: It's definitely gotten more dramatic over the years. We've been filming since 2007, so you can literally go back in time and watch past years, first lectures in particular. And I think the first lecture in 2007 is pretty much me coming out in front of the class saying hello, this is CS50. And we dove into the day's material. 

All right, so welcome to Computer Science 50: Introduction to Computer Science One. My name is David Malan, and I will be your instructor this semester. 

Now there's music. The lights go down. We drop down a huge screen. There may or may not be Muppets in a given year. And it's funny, because this has all happened very gradually over the years, just a little bit more each year. But the delta now between the first year and the last year is actually rather atrocious just how different the first five minutes are. 

AMY: I'm curious, what do you see as the differences between the edX version and the live course? DAVID MALAN: So curricularly and technologically, CS50 on campus and CS50x off campus are fundamentally the same. What does differ between the two is the level of support that we're able to provide. Even though CS50 has a huge team of some 100 teaching fellows, course assistants, myself, and our production team, we can just barely keep up with the 700 students on campus and the 150 extension school students who are local or online themselves. 

And so for CS50x, we simply don't have the support structure of office hours, for instance, four nights a week for several hours. JACK: And what do you guys talk about in office hours that will be different to, say, what you have on lectures, or on sections, or in shorts? DAVID MALAN: On campus office hours are really opportunities for students to pose questions one on one with a member of the teaching staff, or even a classmate of theirs nearby, and generally wrestle with bugs that they're having in their codes. 

AMY: I think Reddit kind of gives a reasonable facsimile of an office hours. 

DAVID MALAN: Agreed, agreed. I've been really impressed, though, with the Reddit community and the newcomers to the group too and just how eager and helpful people have been. And Reddit definitely lends itself better, I think, to posting of code and having threaded discussions. 

JACK: And do you think people should try, if they know they're doing something wrong, or it's like they've implemented it, like spent too much time on it, then they should stop and start again, or look for help, or how should they-- 

DAVID MALAN: Take a break minimally. Sometimes, especially for me at least as your stress level starts to rise, you start hacking away and copying and pasting, forgetting what you've already tried, it's just time to go to sleep, or go take a jog, or go shower, and just kind of get some distance. This has happened many, many times to me where I'll be lying there in bed even, or even driving to work or walking somewhere, kind of debugging in my head. And knowing once you have that distance and a lot less stress on your shoulders, I think can you realize like, oh, you're an idiot. Like I had forgot to call this function or initialize some variable. 

So as a little surprise, if you'd like to take a look under your CS50 seat cushion, a little something awaits you. Those were good looks. We get those looks? [LAUGHTER]