So there's many dimensions to understanding the observations that we just made about sequential decision making. Let's turn our focus to a particular model, from 1992, for sequential decision making, the number guessing experiment. So, consider a group of people that are lined up to play a game in which they will guess a number. So, the number is known to be 0 or 1. No person knows whether it is 0 or 1. So the idea is that every person is going to come to the blackboard, and they're going to make a guess to whether it's 0 or 1. So people that are lined up behind this blackboard and they're all going to come up one at a time and write their guess in. So one person does 0, next person does 1, so forth. So as each person goes up to make a guess, there's a moderator who's standing by the blackboard. And the moderator shows that person either a 0 or a 1 on a card. So he's going to show this person privately either a 0 or a 1. In this case I'm saying it's a 0. And the moderator knows what the true value is what the actual number is. You can think that the moderator came up with the number, he's chosen either a 0 or a 1. And he's going to show every person the number on a card. So each person who comes up doesn't know whether what they're being shown is the right or the wrong value. But everybody knows that there's a higher chance that the card is right than it's wrong. So, if the true value is 0, what that means is that there's a higher chance that they're going to be shown a 0, than a 1. But, they don't know what the true value is. So basically what that means, in a sense, is that as everybody goes through, if there's 100 people guessing, for instance, more than half of them are going to be shown the true value, and less than half of them are going to be shown the false value. So every person that comes up, observes the guesses of those before, which are the public actions. So when you come up to make a guess you get to observe what's currently on the board before you make your own guess. Say, maybe you put a 1 down here as your guess, and the private signal is what was shown to you on a card. So every person gets this private signal that they see, but nobody else can see what the person in front of them was shown on their card. They can only see the public action, what guess that they took. So, what you want to do is use the information that you have, which consists of your own private signal and the public actions involved those before you, which are up on the board to make a guess. So, just to give some terminology and to walk through a simple case right here, when Person 3 goes up, which is showing here. This would be Person 3 because there's two guesses already. He observes PUB 1, which is Public Action 1, PUB II, which is Public Action II, so this would be PUB I and this is PUB II. And he observes PRV III which is private signal 3. And this is private signal 3, which is on the card. So he observes these two and then the he observes his own private signal and he makes his guess which is you, and his guess is PUB III.