Quantification of the relative importance of group members in order to determine a collective pre-ordering

The notion of the power or the relative importance of the groups' members was often neglected in works related to the group decision-making. However, in real group decision-making situations, members having, for example, expertise or occupying a privileged hierarchical level in an organization could have more influence than the others on final recommendation. In such context, the question is how to determine the relative importance of each member? In this work, we propose a method to quantify, for each pair of actions, the relative importance of the members. This method is based first on revised Simos and Degroot methods and second on the exploitation of individual preference structures.