​Fuzzy sets are adequate forms of knowledge representation when the information in uncertain due to vagueness and imprecision.  Knowledge structures using fuzzy sets are similar to those implemented in non-fuzzy systems.  Classical knowledge elicitation methods can be used in combination with techniques to develop membership functions.  The fuzzy set representation has several advantages, including flexibility in expressing uncertain knowledge during elicitation, representation of the knowledge and its uncertainty as a unique entity, easy interfacing with classical systems, and a more robust system in ill-defined domains.  These advantages result in increased system reliability.