Modelling in Natural Sciences
Zwar weifl ich viei, doch macht' ich alles wissen 1 Goethe, Faust 1, Vers 601 Man has always recognized his limitations as a challenge to strive for new hori zons. Today, technical progress enables him to realize this ambition; one of the means are models granting new insights into phenomena or problems which can not be observed or (otherwise) explained. Depending on the standpoint of the ex pert, the model is either mainly retrospective - like Darwin's theory of natural selection as a model to explain the evolution of species - or it concentrates pro spectiveiy on the future by trying to predict events, e. g. catastrophes such as floods or droughts. Naturally, all these models are not perfect as they are man made, but they do help to solve problems. Politicians should draw consequences from these observations; but as they cannot be expected to evaluate such models, they need highly qualified advisers. This exposition already indicates that the terrn model encompasses many dif ferent facets with far-reaching consequences. We quote several examples in order to demonstrate the rather indefmite interpretation of the terrn and the various pur poses models are to serve; in fact we come to the conclusion that there are literally 'models everywhere'. Diverse as models are, they all share some common ideas such as the structural aspects of the modelling process.
Detailed descriptions of examples from various fields of application demonstrating the concepts developedGeneral definition of modelling covering all of its spectrum of applicationUnambiguous epistemic posting of models relative to theories and 'reality'Systematic approach towards models' set-up using concepts of systems analysisEvaluation of models consistent to different applications