The entity–relationship (ER) model, a powerful means for business and data modeling, needs to be enriched with new semantics as the real world changes and its understanding improves. This paper attempts at enriching the ER model based on association rules (AR) discovered from large databases by introducing specializations and sub-types into the ER model. The proposed framework is extended to deal with more general, flexible and linguistic knowledge in fuzzy association rules. Moreover, transforming an AR-enriched-ER (AR-EER) schema to a relational database (RDB) schema is also investigated. Ó 2006 Elsevier Inc. All rights reserved.