Supporting Consensus Reaching Processes under Fuzzy Preferences and a Fuzzy Majority via Linguistic Summaries

Abstract

We consider the classic approach to the evaluation of of degrees of consensus due to Kacprzyk and Fedrizzi [6], [7], [8] in which a soft degree of consensus has been introduced. Its idea is to find a degree to which, for instance, “most of the important individuals agree as to almost all of the relevant options”. The fuzzy majority, expressed as fuzzy linguistic quantifiers (most, almost all, ...) is handled via Zadeh’s [46] classic calculus of linguistically quantified propositions and Yager’s [44] OWA (ordered weighted average) operators. The soft degree of consensus is used for supporting the running of a moderated consensus reaching process along the lines of Fedrizzi, Kacprzyk and Zadrozny [3], Fedrizzi, Kacprzyk, Owsinski and Zadrozny [2], Kacprzyk and Zadrozny [22], and [24].