Managing non-homogeneous information in group decision making

Within the frame of decision aid literature, decision making problems with multiple sources of information have drawn the attention of researchers from a wide spectrum of disciplines. In decision situations with multiple individuals, each one has his own knowledge on the alternatives of the decision problem. The use of information assessed in different domains is not a seldom situation. This non-homogeneous information can be represented as values belonging to domains with different nature as linguistic, numerical and interval valued or can be values assessed in label sets with different granularity, multi-granular linguistic information. Decision processes for solving these problems are composed by two phases: aggregation and exploitation. The main problem to deal with non-homogeneous contexts is how to aggregate the information assessed in these contexts? In this paper, taking as base the 2-tuple fuzzy linguistic representation model we shall develop an aggregation process for dealing with non-homogeneous contexts. In first place, we shall develop an aggregation process for combining numerical, interval valued and linguistic information, afterwards we shall propose different extensions of this process to deal with contexts in which can appear other type of information as intuitionistic fuzzy sets or multi-granular linguistic information. 2004 Elsevier B.V. All rights reserved.