Type-2 Fuzzy Sets and Systems - Computing With Words

Another application for fuzzy sets has also been inspired by Prof. Zadeh (–)—Computing With Words. Different acronyms have been used for "computing with words," e.g., CW and CWW. According to Zadeh:

CWW is a methodology in which the objects of computation are words and propositions drawn from a natural language. inspired by the remarkable human capability to perform a wide variety of physical and mental tasks without any measurements and any computations.

Of course, he did not mean that computers would actually compute using words—single words or phrases—rather than numbers. He meant that computers would be activated by words, which would be converted into a mathematical representation using fuzzy sets and that these fuzzy sets would be mapped by a CWW engine into some other fuzzy set after which the latter would be converted back into a word. A natural question to ask is: Which kind of fuzzy set—type-1 or type-2—should be used as a model for a word? Mendel (, 16]) has argued, on the basis of Karl Popper's concept of Falsificationism (, 30]), that using a type-1 fuzzy set as a model for a word is scientifically incorrect. An interval type-2 fuzzy set should be used as a (first-order uncertainty) model for a word. Much research is under way about CWW.