The OODA loop also serves to explain the nature of surprise and shaping operations in a way that unifies Gestalt psychology, cognitive science and game theory in a comprehensive theory of strategy. Utility theory (the basis of game theory) describes how decisions are made based on the perceived value of taking an action. The OODA loop shows that prior to making a decision (the "decide" phase), the person will first have to get information ("observe") and determine what it means to him and what he can do about it ("orient"). In this way, the utility sought at the "decide" phase can be altered by affecting the information the opponent receives and the cognitive model he applies when orienting upon it.