As ontology development becomes a more ubiquitous and collaborative process, ontology versioning and evolution becomes an important area of ontology research. The many similarities between database-schema evolution and ontology evolution will allow us to build on the extensive research in schema evolution. However, there are also important differences between database schemas and ontologies. The differences stem from different usage paradigms, the presence of explicit semantics and different knowledge models. A lot of problems that existed only in theory in database research come to the forefront as practical problems in ontology evolution. These differences have important implications for the development of ontology-evolution frameworks: The traditional distinction between versioning and evolution is not applicable to ontologies. There are several dimensions along which compatibility between versions must be considered. The set of change operations for ontologies is different. We must develop automatic techniques for finding similarities and differences between versions. Keywords: Ontologies; Ontology evolution; Schema evolution If we trace the evolution of ontology research in computer science, we can see that, as the field grows and matures, the focus of research and the questions that the researchers address shift as well. The progress naturally reflects the shift from more theoretical issues in ontology research to the issues associated with the use of ontologies in real-world, large-scale applications. The active research in ontologies started with defining what a formal ontology is and what requirements an ontology must satisfy (Gruber 1993) . The term ontology came to refer to a wide range of formal representations from taxonomies and hierarchical terminology vocabularies to detailed logical theories describing a domain.
In REF , the authors, in the context of ontology-evolution frameworks, analyze the similarities between database-schema evolution and ontology evolution which allow to develop an extensive research in schema evolution.
Ontology Evolution: Not the Same as Schema Evolution
Knowledge and Information Systems
Knowledge and Information Systems
Computer Science