how to validate and check its fitness. In this respect, Holmes and Cunningham describe a typical case of KBS construction
where expert knowledge can debug and validate the set of rules gathered from DM (Holmes & Cunninghan, 1993). The ‘‘Explora’’ data mining tool is used to build and maintain the ES.
‘‘Explora’’ is a statistics-based mining program that applies domain knowledge and statistical measurements of the database to identify patterns of attribute values and value combinations that occur more or less frequently in the database. The discovered knowledge is debugged and validated by the expert and built into the ES.