So there's many aspects to Netflix in terms of a network setting. one of which is the video streaming system and we'll look at the Internet a little more in a future lecture and the technical aspect of that, but right now we're going to focus more on the social networking aspect. And we're going to focus specifically on how they recommend movies for you to watch. So how those recommendation schemes work and so recommendations really kind of a cool thing because it's like we're mind reading. Right, we're reading your mind to predict what we think, what movies we think you would like depending upon what you have rated and so on, and the similarities between what you rated and the movies that you haven't watched. And and then we make a prediction. We say we'd think you'd also like this movie, and so when you go onto Netflix site and you're browsing through movies, for each one you kind of have three different options. Right? You can, you can either rate it. Right here we're showing that you can you know, give it a certain star rating. If you want. you can add it to a queue if you actually want to watch it. so, if you wanted to watch this movie, for instance. You could say, alright put it in this cue. Whatever, there's different cues that you can have to watch. Or you can say, you're not interested. Right? If you click this Not Interested button, that's also very useful feedback to Netflix. And to say, don't recommend this movie to me. It might also say, okay, well, those types of movies you don't want to see, for instance. And so each of these things that you do, whether it's rating, add into the queue, or saying you're not interested, all impact the movies that are going to be recommended to you. And so you're encouraged again, the more input that you give the better the recommendation method will be for you specifically. And so this is the idea of recommending in Netflix where we're recommending movies for you to watch. Before we move on to talk just about Netflix's recommendation let's bring up a few other applications where we see recommendation on the Internet. There's, obviously everywhere this is happening, but just a few notorious examples. First is YouTube. YouTube You Tube has a bar where they recommend videos, that they think you should watch, and the way that they do that is interesting. They leverage what's called the co-visitation count, which basically says, I'm going to recommend to you some movies that have also been watched by other users. And that, that have also watched the same movie that you've watched, right? So, if you watched a couple movies. Then other people, they look at the other people who also watched that movie. And then they'd look at the movies that the other people have watched in the past 24 hours or so. And then they say, okay. You'll probably like these movies too. on Amazon they recommend products to you. So they'll say they'll look at the list of products that you've bought, similar items therof, they'll look at people who have bought the same products as you and the other products they've bought and they'll try to recommend things for you to buy. And on Pandora they recommend songs, so they actually have a bunch of experts that deal with those recommendations. And you also have a binary up and down, or thumbs up, or thumbs down voting on Pandora which indicates what songs get recommend to you and influences that strongly. So for instance, on Amazon, they just show this recommended to you right here. It's right now recommending a book for me, which is on networking, front end engineering and for building websites, which is pretty similar to this course. And then on YouTube, this is just showing types of videos that they recommend to you based on what you've watched, and. Now you can see my musical taste. And if you can go onto, YouTube you might be able to see that they tend to do a pretty good job of recommending videos that you might want to watch. That's how people tend to get hooked on YouTube. In the optional reading, again for this course, we do have a whole other chapter on YouTube as well that we talk about. some of the other aspects of YouTube. Like spreading of information.