1. An Approach to Cope with Ontology Changes for Ontology-based Applications Yaozhong LIANG, Harith ALANI, David DUPPLAW, Nigel SHADBOLT {y.david.liang | ha | dpd | nrs}@ecs.soton.ac.uk Intelligence, Agents and Multimedia Group, School of Electronics and Computer Science, University of Southampton Ontology Change Management There have been a lot of research activities related to ontology changes thriving so far. Most of them could fall into one or more of three groups as following: Detection and characterisation of change; Ontology versioning and evolution; Handling inconsistency introduced by ontology change; Not much has been done with respect to using change- tracks to eliminate or reduce any impacts that ontology change can have on any dependent applications and services. Our Approach The design in our approach aims at taking advantage of change-tracks to reduce any impacts on the dependent applications and services brought by the changes on the underlying ontologies. Capture: manually located changes by comparing two variants using Protégé. Manage: based on the identified changes above, Log Ontology was designed to represent the changes. Analyse: the incoming RDQL queries was analysed to find out their effectiveness and usability by checking each entity within the queries coordinating with Log Ontology. Access: if certain entities within the users queries were found being updated to the new versions, they would be replaced by their relevant new versions to form the new queries, and then submitted to applications/service for execution. Response: change/update information would return along with the queries results to the end-users so as to update users domain knowledge in the due course. Discussion and Future Work We have implemented a prototypical implementation of this middle layer infrastructure for ontology-based systems and successfully tested it on CRM ontology. We showed that with extra support of the middle layer ontology-based system could provide continuous and unchanged services to the end-users without the deleterious effects brought by the changes of underlying ontologies, in the meantime, the interested end-users could also get the knowledge of up-to-date changes taken on the underlying ontologies. Some ideas we would like to research and discuss further: Log Ontology: the middle layer infrastructure depends on the structure and change information organisation of Log Ontology. The methods to increase the flexibility of this infrastructure to adapt the modification of the Log Ontology will provide the extra power to make our approach a crystal interface for another ontology-based applications/services. Applications/Service: due to the quantity and quality of changes captured in the Log Ontology, our approach to cope with the different kinds of ontology changes could not be a complete list. Other applications/services to enlarge the scope of the investigation related to the types of ontology changes would be necessary. The issue about changes: our focus in the approach is on how to deal with the changes of the entities within the users queries. How about the changes indirectly related to entities within the queries? When and how to inform the users of them? Some changes to the entities in the queries dont affect the results the queries, yet some do! Should we tell the end-users about these kinds of changes? How could we judge whether the end-users need this information? Acknowledgements This work is supported under the Advanced Knowledge Technologies Interdisciplinary Research Collaboration, which is sponsored by the UK Engineering and Physical Sciences Research Council under grant number GR/N15764/01. The AKT IRC research partners and sponsors are authorized to reproduce and distribute reprints and on-line copies for their purposes notwithstanding any copyright annotation hereon.