Modelling policy consequences and evaluation processes using the "deduc" nonnumerical program system

Abstract

The reality which global models are supposed to model contains many crucial processes (ecological and social development, human decision-making, etc.) which cannot be properly modelled by numerical methods and must be represented by the logical processing of qualitative, nonnumerical information. We have developed, and are using for these purposes, the DEDUC nonnumerical processing system based on the predicate calculus. Elements of the system are briefly described. It has proven itself very useful and reliable in processing large amounts of qualitative data for a) deducing impacts and consequences of events, actions or policies (environmental impact assessment is a typical application) and b) for obtaining impact evaluations from the point of view of given social actors in order to obtain reliable assessments of likely attitudes and behavioral trends concerning given events, actions or policies. Supplementing quantitative global models with qualitative models of relevant non-quantifiable processes would improve their analytical and predictive quality significantly.

Paper based partially on unpublished research by K.F. Müller-Reissmann, B. Hornung, and R. Schiefer of ISP.