Date of Original Version
Abstract or Table of Contents
Abstract: "In modeling, as in any other human activity, there is a certain amount of historical inertia. Predictive models bulked large in the early history of modeling. In our enthusiatic efforts to explore the potential of computers we tended to conceptualize computers as number crunchers, and were not immediately able to see the potential for qualitative and symbolic modeling that did not use numbers.Before we begin a modeling task, we need to answer the following: Whether we need temporal detail, and if so, what amount can be supported by the kinds of data and theories that we have available; whether a good understanding of steady states may be more important to us than tracing paths; whether we can simplify the systems we are modeling by making use of their hierarchical properties to aggregate, or in other way [sic]; are there aspects of the situation of interest that are better modeled symbolically, in words or pictures, rather than numberically [sic]?"