The first is observation, we should look at what people actually do. If the $20 bill is still there, pick it up. If people respond in a certain way to a stimulus, then we should learn something from that. As opposed to just focusing in our theories about what's going on. The second is the importance of feedback loops. When the person involved see some feedback on their behavior which they can then observe it tends to produce a response and that process that circular process of action and feedback and response tends to motivate behavior and that's a powerful process to understand for gamification. And finally the notion in behaviorism of reinforcement. That learning occurs by the reinforcement of stimuli, when more and more you see that a certain action produces a certain result you tend to learn and make that association.