Autocratic decision making using group recommendations based on interval type-2 fuzzy sets, enhanced Karnik-Mendel algorithms, and the ordered weighted aggregation operator

Autocratic decision making using group recommendations (ADMUGRs) is a very important research topic in the research area of multiple attributes group decision making (MAGDM), which automatically modifies the weights of decision makers (DMs) to get MAGDM results. In this paper, a new method for ADMUGRs is proposed based on interval type-2 fuzzy sets (IT2FSs), enhanced Karnik-Mendel (EKM) algorithms, and the ordered weighted aggregation (OWA) operator. Each DM uses linguistic terms represented by IT2FSs to evaluate the attributes of alternatives, where different attributes can have different weights in [0, 1]. The evaluating matrices (EMs) and the weighting vectors (WVs) of the attributes given by the DMs are assessed by linguistic terms represented by IT2FSs. The proposed method can overcome the shortcomings of Chen and Hong's method (2014), Chen and Lee's method (2010) and Cheng et al.'s method (2016) for ADMUGRs in IT2FSs environments.