Type-2 fuzzy soft sets and their applications in decision making

Molodtsov introduced the theory of soft sets,which can be used as a general mathematical tool for dealing with uncertainty. this paper aims to introduce the concept of the type-2 fuzzy soft set by integrating the type-2 fuzzy set theory and the soft set theory. some operations on the type-2 fuzzy soft sets are given. furthermore,we investigate the decision making based on type-2 fuzzy soft sets. by means of level soft sets,we propose an adjustable approach to type-2 fuzzy-soft-set based decision making and give some illustrative examples. moreover,we also introduce the weighted type-2 fuzzy soft set and examine its application to decision making. © 2012 zhiming zhang and shouhua zhang.