9311494 Kellert The field of nonlinear dynamics has enjoyed tremendous growth in recent years. Researchers in the physical, biological, and social sciences have found the methods and techniques to be useful for investigating linear models when they break down because of effects such as friction or feedback that introduce strong nonlinear terms into their idealized systems. The study of strongly nonlinear systems often reveals highly complex and unpredictable behavior even in very simple mathematical models, and this phenomenon has been called "chaos." The scientific investigation of chaotic behavior is popularly known as "chaos theory." The popularization of chaos theory has also invited some misunderstandings. Here the philosophy of science can be of some public and professional help in removing confusion and critically evaluating the claims made. Further, as a field of investigation which is even now enjoying dramatic growth and change, nonlinear dynamics provides an excellent situation for philosophy of science to make contact with scientific knowledge in the very process of its construction. Under this grant, Dr. Kellert is continuing his efforts to improve our understanding of the structure of non-linear dynamics, the new techniques associated with it, and the general impact it will have on our conception of science. In particular, he is applying an examination of the modeling techniques used in the study of chaotic systems to the questions of the structure of scientific theories and the nature of the relationship between different sciences. ***
