Evaluating the validity of data instances against ontology evolution over the Semantic Web

It is natural for ontologies to evolve over time. These changes could be at structural and semantic levels. Due to changes to an ontology, its data instances may become invalid, and as a result, may become non-interpretable. In this paper, we address precisely this problem, validity of data instances due to ontological evolution. Towards this end, we make the following three novel contributions to the area of Semantic Web. First, we propose formal notions of structural validity and semantic validity of data instances, and then present approaches to ensure them. Second, we propose semantic view as part of an ontology, and demonstrate that it is sufficient to validate a data instance against the semantic view rather than the entire ontology. We discuss how the semantic view can be generated through an implication analysis, i.e., how semantic changes to one component imply semantic changes to other components in the ontology. Third, we propose a validity identification approach that employs locally maintaining a hash value of the semantic view at the data instance.