Reflexive Ontologies: Enhancing Ontologies with Self- Contained Queries In: Journal of Cybernetics and Systems (2008) Volume 39, Issue 2 © 2008 Taylor & Francis, Inc. C. Toro 1 , C. Sanin 2 , E. Szczerbicki 2 , J. Posada 1 1 VICOMTech Research Centre, Paseo Mikeletegi 57, bajo Donostia-San Sebastian, Spain Tel:+34 943309230, Email: ctoro@vicomtech.org 2 University of Newcastle, Newcastle, Australia Abstract: In this article, we introduce the concept of “Reflexive On- tologies”. A Reflexive Ontology is a description of the con- cepts and relations of such concepts with a set of self con- tained queries over instances in the domain of study. The enhancement of having self contained queries relies in (i) the speeding of the query process (ii) the possibility of the ontology itself to add new queries on individuals with the correspondent answers to such queries (a feature that adds knowledge about the domain); and (iii) the self con- tainment of the Knowledge Structure in a single file; includ- ing the model, the relations between the elements of the model, the individuals (instances) and queries over such individuals. We present in this article a framework that can be used to extend any existing ontology with the reflexivity approach we introduce. Additionally, and as a case study, we test the architecture with a previously presented knowledge struc- ture called Set of Experience Knowledge Structure (SOEKS). Keywords: Knowledge Engineering, Reflexive Ontologies, Set of Experience Knowledge Structure. 1 Introduction Semantic technologies constitute one of the most interesting technologies derived from the World Wide Web revolution. Constantly reviewed in different areas of knowledge (e.g. Linguistics), their greatest improvements for information technologies could be still there to discover. It is true that the whole concept of the semantic web presented by Tim Berners-Lee [2] in his foundational article is still not reached yet, according to some members of the scientific community, but the improvements present in today’s Web sites and search engines are not to be underestimated. Within the myriads of semantic based techniques available, a great attention has been given to ontologies and how their implementation and use enhance real world applications that are not directly related to the Web itself. One of the biggest interests in ontologies is their flexibility and capa- bility to model a domain and hence, conceptualize the por- tion of reality to which such domain refers to. It is not enough to have a good modeled ontology fed with real world instances (individuals) from trustable sources of in- formation. Nowadays, it is of the utmost importance to enhance the ontologies with the capability of querying their knowledge models in a fast and trustable way. In this article, we introduce the concept of “Reflexive On- tologies” as a technique that can be used to add self con- tained queries to an ontology. Selected Readings in Computer Graphics 2008 149