Abstract: Experts often give heterogeneous types of preference information, such as fuzzy preference relations, interval reciprocal preference relations and linguistic preference relations, in a group decision making environment. A new method was developed for aggregating these three types of preference relations, whose basic idea is that different kinds of information are transformed into an intermediate field (an utility space) before they are aggregated. The advantage of this method is that the direct inter-conversion among those different kinds of preference information is avoided and the computation process is more simple. Firstly, considering fuzzy preference relations, interval reciprocal preference relations and linguistic preference relations, these preference relations were transformed into fuzzy preference relations based on the idea of utility, and the reasonability in the transforming process was discussed. Then an approach was provided to aggregate those kinds of information and select the best alternatives in the group decision making process. Finally, the practicability of this method was illustrated with an example.

Key words: group decision making, heterogeneous types of preference information, transforming method, aggregating process