The unbalanced linguistic aggregation operator in group decision making

In decision making problems, experts need to assess a number of values in a side of reference domain higher than in the other one,that is, experts use unbalanced linguistic values to express their evaluation for problems. In this paper, we propose a new linguistic aggregation operator to deal with unbalanced linguistic values in group decision making. Based on 2-tuple representation model of linguistic values and linguistic hierarchies, we express unbalanced linguistic values. Moreover, we present the unbalanced linguistic ordered weighted geometric operator to aggregate unbalanced linguistic evaluation values. Some properties of the unbalanced linguistic ordered weighted geometric operator are also obtained. An illustration example shows the proposed approach seems more effective for linguistic group decision making problem.