Normalisation of ontology implementations: Towards modularity, re-use, and maintainability

Abstract. There is a long history of standard normal forms for informa-tion models for databases. However,no analogous notion of normalisation for ontologies has yet emerged. This paper proposes initial criteria for normalisation of \rigorous formal ontologies " to promote a) domain cor-rectness, b) utility, c) re-use, d) modularity, e) maintainability, and f) evolution. The normalisation is in two stages. For the rst | \ontological normalisation " | we accept Welty and Guarino's analysis. The second |\implementation normalisation " | is the primary focus of this pa-per. For \implementation normalisation " we propose an approach based on decomposing or \untangling " the ontology into independent disjoint taxonomies which are then recombined using denitions and descriptions which link relevant concepts in the decomposed taxonomies.