Hesitant linguistic expression soft sets: Application to group decision making

The notion of linguistic value soft set was proposed to handle linguistic decision making problems under uncertainty. It is based on soft set theory and the fuzzy linguistic approach. However, in real-world situations the decision makers may not only need single linguistic terms to elicit their knowledge about alternatives but also more elaborate linguistic expressions such as, comparative linguistic expressions. Linguistic value soft sets cannot deal with these situations in a satisfactory manner. Hence, we propose one step further towards a complete combination of soft set theory and hesitant fuzzy linguistic term sets to put forward a new model called hesitant linguistic expression soft set that facilitates the elicitation of linguistic information with soft sets. Afterwards, a novel multi-criteria group decision making approach with a consensus reaching process, by using hesitant linguistic expression soft sets, is presented. Some illustrative examples show the feasibility and implementation of our novel proposals.