Such research is usually necessary to move from a stated social concern to the formulation of an informed and rational policy decision. However, research designed to resolve a problem is often begun before the problem is clearly defined or understood. In addition, the use of different analytical paradigms may result in different policy conclusions, although researchers often fail to recognize this fact. Furthermore, statistical models are often assumed to fit the real world. Thus, analysts must choose among various approaches to the problem and then make underlying assumptions in selecting a methodology. They should recognize that system dynamics and data analysis are alternative analytical paradigms that have much to contribute to understanding policy issues.