In: G. Lindemann, C. Jonker, I. Timm (Eds.): Proceedings of the Third International Workshop on Modelling Artificial Societies and Hybrid Organizations (MASHO'02), Workshop at the 25th German Conference on Artificial Intelligence, Aachen, Germany, September 16, 2002, pages 47-56. September 2002. Available online at: http://www.informatik.hu-berlin.de/~lindeman/masho02.