A rule based fuzzy decision model for simple lotteries

This article introduces a liberal alternative to the well-known decision mo dels under risk in the form of a rule-based fuzzy decision model. The struc ture of the model corresponds to a simple, knowledge-based (expert-)system, which is capable to justify its assumptions and conclusions. On the basis of empirical data the computer program models the inference processes of hu man decision makers in fuzzy-categories and rubs: of decision. The model cl aims to reproduce decision processes with risky alternatives more adequate than conventional models. In comparison with human test subjects the comput er-based decisions produced strong correspondences with regard to the choic e of the same alternatives.