OWL and OCL for Semantic Integration

OCL (Object Constraint Language) is an expression language to specify constraints and to refine UML diagrams to make them understandable for a computer. It is an important language in Model-Driven Architecture (MDA). OWL (Web Ontology Language) is an ontology language for semantic Web. So what is the relationship between OCL and OWL? Can they complement each other for semantic integration? We emphasize three points on OWL and OCL. First, OWL and OCL have more differences than similarities and some complementary roles exist. Second, for semantic integration OWL can be used for modeling public and shared knowledge as widely known whereas OCL can be used for modeling private constraints. Third, OCL can be used a basis for building Ontology Query Language (OQL).