1. Introduction

The overall objective of decision support systems (DSSs), whether individual or group based, is to counterbalance decision makers’ intuition, against rational techniques or models (multicriteria decision-aiding methods for instance), in order to improve decision-making. As a side effect, using DSSs also appears to reduce decision time, enhance user satisfaction, improve the ability to explain the reasons for deciding and accepting those decisions (i.e., decision reconstruction [1]), and facilitate knowledge acquisition (see, for instance, [2–4], for further insights, as well as [5– 7] for some of the process drawbacks). Decision-making can be seen as an organizational routine [8], traditionally consisting of an organized task, which requires the contribution of cooperative groups. According to [9], such groups have specific properties and they act in contexts that are different from the ones of negotiation, in the classic sense of that term. The characteristics that distinguish the two situations arise from differences in goals and objectives convergence, power relationships and interdependencies that are normally present, the possibilities of sharing information, and relevant behaviors (not to abandon a negotiation for instance). In the context of this work, a cooperative group is constituted by individuals who wish or need to reach a cooperative solution and that, therefore, are willing to contribute to the shared understanding of a problem [10].