3. The system according to claim 1, further comprising: a clustering fuzzy evaluator for calculating and storing a clustered fuzzy expected value for each record in the database, wherein the membership grades are grouped into clusters according to the predetermined formula, and wherein the clustered fuzzy expected value for each record in the database is calculated based on a mean of the membership grades for all words in the list of relevant words and on each mean of the membership grades in each of said clusters.
3. The system according to claim 1, further comprising: a clustering fuzzy evaluator for calculating and storing a clustered fuzzy expected value for each record in the database, wherein the membership grades are grouped into clusters according to the predetermined formula, and wherein the clustered fuzzy expected value for each record in the database is calculated based on a mean of the membership grades for all words in the list of relevant words and on each mean of the membership grades in each of said clusters. 7. The system according to claim 3, wherein the clustering fuzzy evaluator calculates the clustered fuzzy expected value for a record containing three or more words according to ##EQU23## where W.sub.A is the mean of membership grades for all words in the record containing three or more words and is calculated according to ##EQU24## where W.sub.Ai is the mean membership grade associated with one of the plurality of clusters of said membership grades and is calculated according to ##EQU25## and where N equals the number of words in the record containing three or more words, i designates a cluster, a.sub.ij is the number of words in the cluster having membership grade x.sub.ij, m is the number of clusters, n is the number of words in a cluster, x is a parameter based on the field of use of the CFEV, N.sub.i is the number of words in cluster i.