Ontology Change Management in Protégé

Ontology schemas tend to change and evolve over time to meet new requirements. This change may invalidate dependent applications if there is no dynamic adaptation to the changes made to underlying ontologies. Protégé, as a popular ontology development tool, should meet the challenges addressed by the evolving ontology. In this paper, we will briefly analyse the current ontology-change management in Protégé, and propose some extensions to facilitate change traceability by external application and services. 1. Ontology Management Ontologies are becoming the corner stone of the Semantic Web (SW). Ontologies often continue to evolve over time due to domain changes, adaptations to different applications, changes to our conceptualisation or understanding of a domain, etc. Unfortunately, appropriate tools for managing ontology evolution efficiently are still missing [4]. Ontology versioning provides the mechanism to store and identify various versions of the same ontology and to highlight their differences. Ontology comparison helps ontology engineers to locate changes between different versions of an ontology [1]. If conceptual relations between various versions are built up, it becomes possible to re-interpret the data and knowledge under the different versions so that incompatibility caused by the changes made to the ontologies could be resolved semantically [2]. The lack of dynamic response to changes made to underlying ontologies may hamper the effective use of those ontologies by dependent applications. For such applications to recover and update their calls to the changed ontology, they might need to access some information that represents those changes and update accordingly. 2. Change Facilities in Protégé Protégé evolved over the years from the role to reduce the knowledge-acquisition 2 Yaozhong LIANG, Harith ALANI, Nigel SHADBOLT bottleneck in constructing knowledge bases to an extensible, customisable, and more general-purpose toolset for constructing knowledge bases (KBs) and developing KB-based applications [3]. As ontology development became a more ubiquitous and collaborative process, to maintain Protégé’s robustness in future ontology-related applications, support for ontology management becomes essential and necessary. This support should allow the ontology developers to examine and understand the changes and their rational, and enable any dependent applications to remain up to date and compatible with the latest version of the ontology. The following sections will describe the current change facilities supported by Protégé. In section 3 we will give out a set of requirements for a more Semantic Web friendly change management in Protégé.