Fig. 1. Management of natural resources involves a mental model of how the real world responds to influences by the manager (thin arrow), as well as influences outside the managers’ control (thick arrow), and how this overall response is reflected in performance indicators that will (partially) satisfy a set of multiple objectives. The contrast between the expected system performance and objectives may lead to a change in the managers’ inputs into the real-world situation. Actual experience may lead to learning, in the sense of modifying the mental model, and changing the scenarios and plans. Because the real world involves many layers of “managers,” there will be considerable feedback outside of the managers’ control. The diagram shows a “national policy” management level superimposed on a “farmer” management level, superimposed on the real world.