A. Gmez-PØrez and V.R. Benjamins (Eds.): EKAW 2002, LNAI 2473, pp. 285-300, 2002.  Springer-Verlag Berlin Heidelberg 2002 User-Driven Ontology Evolution Management Ljiljana Stojanovic 1 , Alexander Maedche 1 , Boris Motik 1 , Nenad Stojanovic 2 1 FZI - Research Center for Information Technologies at the University of Karlsruhe, Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe, Germany {Ljiljana.Stojanovic,Alexander.Maedche,Boris.Motik}@fzi.de 2 Institute AIFB, University of Karlsruhe, 76128 Karlsruhe, Germany nst@aifb.uni-karlsruhe.de Abstract. With rising importance of knowledge interchange, many industrial and academic applications have adopted ontologies as their conceptual backbone. However, industrial and academic environments are very dynamic, thus inducing changes to application requirements. To fulfill these changes, often the underlying ontology must be evolved as well. As ontologies grow in size, the complexity of change management increases, thus requiring a well- structured ontology evolution process. In this paper we identify a possible six- phase evolution process and focus on providing the user with capabilities to control and customize it. We introduce the concept of an evolution strategy encapsulating policy for evolution with respect to users requirements. 1 Introduction With rising importance of knowledge interchange, many industrial and academic applications have adopted ontologies as their conceptual backbone. However, business dynamics and changes in the operating environment often give rise to continuous changes to application requirements, that may be fulfilled only by changing the underlying ontologies [16]. This is especially true for WWW and Semantic Web applications [2], that are based on heterogeneous and highly distributed information resources and therefore need efficient mechanisms to cope with changes in the environment. Ontology evolution is the timely adaptation of an ontology to changed business requirements, to trends in ontology instances and patterns of usage of the ontology- based application, as well as the consistent management/propagation of these changes to dependent elements. A modification in one part of the ontology may generate subtle inconsistencies in other parts of the same ontology, in the ontology-based instances as well as in depending ontologies and applications [11]. This variety of causes and consequences of the ontology changes makes ontology evolution a very complex operation that should be considered as both, an organizational and a technical process [22]. It requires a careful analysis of the types of the ontology changes [13] that can trigger evolution as well as the environment in which the whole ontology evolution process is realized [25].