Group-based Pythagorean fuzzy soft sets with medical decision-making applications

Abstract

The Pythagorean fuzzy soft set is an instrument to overcome the uncertainty in the data by adding a parametrisation element. Group decision-making is a continuum in which multiple individuals interact at the same time, resolve problems, appraise the probable existing alternatives, characterised by multiple contradictory criteria, and select an appropriate alternative solution to the problem. In this study, the generalised Pythagorean fuzzy soft set and the group-based generalised Pythagorean fuzzy soft set are defined. A group-based generalised Pythagorean fuzzy soft set is to be used in the evaluation of the object by a group of experts rather than a single expert. According to new definitions, weighted averaging and geometric aggregation operators have been given. To solve the problems in the Pythagorean fuzzy environment, the decision-making process established by considering the new soft sets and the aggregation operators obtained with these sets were presented with an algorithm. A medical example of the choice of the optimal alternative has been designed to indicate the developed decision-making process. Finally, a comparison has been made between the new method and the existing method. It is seen from the results obtained that an expert opinion does not give appropriate results at the desired rate without the generalisation parameter.