Learning by Doing

Abstract

Part III focused on understanding system structure: how system variables, such as energy consumed and expended in the human system of energy and weight regulation, are related; how they influence one another; and how they are influenced by our external environment. Along the way, this discussion helped us clear up some of the public’s muddled thinking about human energy and weight regulation, such as the limitations of the energy balance equation. However, as I noted at the close of Chapter 13, understanding system structure is not enough. Effective control of any complex dynamic system, such as the human body, requires a second essential skill: the ability to predict the system’s behavior. The ability to infer system behavior is essential if we are to know how actions taken would influence the system, and thus is essential in devising appropriate interventions for change. So, in Part IV we shift our attention from understanding to predicting.