5.1 Fuzzy Concept and Graded Membership
Concept can be generally divided into two categories. One category includes clearly-defined concepts; these concepts have precise definitions and clear-cut boundaries. For example, the concept expressed by the word car seems to have a clear-cut definition commonly agreed by most speakers. It involves a very specific kind of entity, i.e., a road vehicle with four wheels which is driven by a motor. However, a number of concepts do not have precise definitions and clear-cut boundaries. For example, the concept expressed by the word beautiful does not have a clear-cut definition. The notion of ‘beauty’ is very subjective; it depends on personal perspectives and it varies across cultures. Concepts like this are called fuzzy concepts. Table 6.11 provides more examples of the two categories of concept.