Before we can begin to consider the psychological aspects of interacting and controlling uncertainty, we need to set the scene by fi rst considering the actual mechanisms that drive complex systems. To do this, we need to explore the nature of control systems from an engineering perspective. In this sense what this chapter aims to do is detail the workings of the puppet, the nuts and bolts and theory that help to develop it and what contributes to its unpredictable nature. What will become apparent in this chapter is that while there are properties of the puppet that are well defi ned by theories of engineering, there are properties that cannot be well defi ned, and this means that some aspect of the puppet will remain uncertain.
Nevertheless, identifying the source of uncertainty in a control system should provide a more secure basis from which to fi nd answers to the central question of this book, ' How do we learn about, and control online, an uncertain environment that may be changing as a consequence of our actions, or autonomously, or both? ' This is because if we know how the environment behaves, we can understand better how we react, interact and control it.