We will talk more about sensors in Lecture 2 and thereafter. This is called a representation or an internal model. Robots are programmed to display desired behavior. Behavior is a result of a sequence of robot actions. Observing behavior may not tell us much about the internal control of a robot.
Control can be a black box.
The many different ways in which robots can be controlled all fall along a well-defined spectrum of control. Think hard, act later. Reaction must be fast.