Redefining Dialectical Vague Terms via Fuzzy Set Theory

Vagueness is an intrinsic feature of natural languages. A noticeable number of linguistic terms and variables are not clear, accurate, and certain. Although employing uncertain terms such as accent, dialect, and language variety imply a clear-cut linguistic area, our experience leads us toward a fuzzy division of linguistic area without definite boundaries; these terms are vague. To make the ambiguity of these terms clear, therefore, current study applied fuzzy logic in clustering language varieties and illustrating their linguistic interrelationship. It shows that a variety can belong in one or multiple sets of language varieties simultaneously, to some specific but different values. Truth value or the degree of membership may be any real number between 0 and 1 which accurately represents the relation in the cluster. Therefore, there is no need to accept the integrity of clustering and vagueness implied in terms like language, dialect, and accent in their traditional definition.