On Methodology for Group Decision Support

This paper studies a group decision making process from a general point of view. The former part of the process is the clarification of the basic elements in a group decision situation and the latter part is the analysis of the situation followed by the modification of it. It is shown that several measures appear and are utilized in the process. Furthermore, a method for group decision support — the extended contributive rule method — which contains a power of aggregation as a parameter, is explained in comparison with the concept of partial comparability of individual utilities by Sen.