Validation of Simulation Models

©1999 No part of this book may be reproduced in any form by print, photoprint, microfilm or any other means without the prior written permission from the publisher. A publication in coöperation with the Dutch researchgroups SIMULATION and COMPLEX SOCIETAL PROBLEMS of the NOSMO (Dutch Research group on Methodology) Validation of simulation models in the social sciences Cor van Dijkum and Etzel van Kuijk 7 The validation of metaphors Ferdinand Verhulst 30 Global modeling: managing uncertainty, complexity and incomplete information Marco Janssen and Bert de Vries 45 Graph theoretical analysis as tool for validation and conceptualization Cornelis Hoede and Helene Margot Weening 70 Simulation of educational effects Henny de Vos and Roel J. Bosker 88 Statistical validation of simulation, including case studies Jack P.C. Kleijnen 112 Outside validity of research of complex societal problems Dorien J. DeTombe 128 About the authors 139 4 PREFACE Computer models are more and more used in our society to get grasp on difficult scientific and social problems. In science computer models enable us to understand phenomena, such as turbulence in fluid, that were never understood before. For society threats to mankind, such as a possible climate change or limits to the availability of food and unpolluted fresh water, can be explored with computer models. Science is necessary to accumulate the insight needed for these models. On the other hand scientists can not work without computer models to handle their complex knowledge. However, with those models old scientific questions are back on the stage: how valid is the knowledge provided by the models ? How are the facts of the world related to those models ? How sound is the logical reasoning in the models ? There is not an easy answer to such questions. The logic of science which seems adequate for a number of old(fashioned) ways to describe and explain the world, shows its limitations when it comes to the surprises of computermodels. This book is dealing with the challenge posed by computermodels for science. Each year the Dutch Federation of Social Science Methodology (NOSMO) discusses actual (methodo)logical problems. In 1997 one of the themes reflected was the question of the validation of knowledge generated by computer models. Authoritative lecturers from different disciplines (inside and outside of the social sciences) were invited to explain how they dealt with this question in their field. The written examinations of that sessions were starting points for …