Initially, modelling of the decision process was based on the comparison and the establishment of the preference ordering of the various options of a decision problem in terms of utilities and values (Keeney & Raiffa, 1976; von Winterfeldt and Edwards, 1986). This approach was soon questioned by a number of researchers (Berkeley and Humphreys, 1982; Christensen-Szalanski, 1984), since it relied on the assumptions that the decision making task can be represented in only one correct way, and that the model used constrains the answers to the decision task. This criticism was also supported by a number of studies on intuitive decision making in laboratory experiments, as well as in experiments on real problems in which a normative model has been followed (Tversky & Kahnemann, 1974; Vari et al., 1978). It was found that in structuring "real-life problems", the personal factors of the problem owner, as well as the social constrains relevant to the problem situation, are very determinative and allow for the consideration of the differences between people in handling a decision problem (Humphreys and Berkeley, 1982; Larichev, 1982; Marouda-Chatjoulis, 1995).