So, these examples are about a site called Fitrocaracy, a site to encourage people to exercise, to work out and to get into shape. And Fitrocracy uses all of the standard kinds of PBL type game elements we've seen. But they do it in a fairly coherent sophisticated way, which is really targeted towards intrinsically motivating people, to engage in the activity. So, first here, this is what happens on Fitocrancy when you level up. You get a certain number of points. Standard game element. It says you are a level up, now you're now at level three, and here is the badge that you get for leveling up. But notice how this is all integrated together, it's not just you've leveled up. It's, congratulations! You've earned it! earning, i.e. A sense of competence that you've done something hard, that got you to that next level. You're now level three. Awesome! And the click button says I'm awesome! And you can share it with your friends. To tell them how awesome you are. And this is part of the overall structure of this site. It really wants to make you feel good about yourself, when you exercise, and it wants you to see this as a challenge. And a challenge that when you overcome some of those challenges, when you start to tag and, and report your workouts, and start to move up, and how. Effective your workouts are, that means you are leveling up, not just in some abstract sense, but you are getting better. You're getting into better shape. So, that's all about competence, and again, it's in how the site is designed, to make the person feel, that their activity is achieving something. Mastering something, as opposed to just doing something, for no particular reason.