[MUSIC] Hi again. I'm Leo Porter, I'm a computer science professor here at UC San Diego. One of my areas of research is computer science education. What we like to do in that area of research is look at the best practices for student learning in the classroom. One of the best practices we know about in computer science is peer instruction. With peer instruction, students get to tackle hard problems, discuss it with their peers, and then participate in a large, class wide discussion with the professor. We do this in a number of the courses here at UC San Diego, and we'd like to bring this to you. And we're gonna do this through a series of videos known as the Concept Challenges. So let me walk through an example here. So here we have you watching a video. Now let's assume this is from a previous class in Java that you've taken before where you learned first about for loops. So you watch the video on for loops and then you get done with the video and the question becomes, well, did you learn it? I mean, there's certainly areas of the video that you probably understood well. But there may be areas that you didn't understand as well. So the best way to find out whether or not you really understood the material is to solve problems. So we're going to ask you questions to help illustrate what areas you're strongest in and which areas you're not. So, a question may look something like this. So here's, you just watched a video again on for loops and here's an example for loop. And the question here is asking how many times does i<10 execute? Now, the reason we ask a question like this is because we expect a number of folks will get this wrong. In fact, we want you to get a number of these questions wrong because that means it's an opportunity for learning. What we expect is a lot of novice learners will answer B here. They would say that the loop executes 10 times, so i<10 will execute 10 times. But the condition i<10 actually executes 11 times, and we'll talk more about that as we go forward. So after you solve the problem on your own, after you've tackled the problem yourself, what's you're going to then see, we hope you can do, is work with other learners around you. So if you have anyone else in your neighborhood, or friends who've taken the same course, this is a great time to get together and discuss the question. By discussing with your friends, you're going to find out, one of you might say, but wait a second execute that last time, and then you realize oh shoot, yeah it does actually execute 11 times. But if you don't have some friends around you, what we are going to give you also is a series of videos where you are seeing UC San Diego learners discussing the question. And there you'll hear them say things like, what a second it's really easy to forget that last check. Oh, yeah, so the answer must have been 11. And then, after you hear UC San Diego learners discussing it, you're gonna hear one of our explanations. So the full course of one of these questions is gonna look something like this. You're gonna pause, try solving the problem yourself. You're gonna discuss the question with other learners around you if you can. You're then gonna watch a video of the UC San Diego learners discussing it. And then you're gonna confirm your understanding by listening to our explanation. By solving these kind of hard problems, you're gonna understand your material much better. You're also gonna identify areas that you might need improvement. And that's where more support videos and the forums come in.