BibSonomy publications for /user/eswc2008/q2semanticWed May 28 14:49:54 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSQ2Semantic: A Lightweight Keyword Interface to Semantic Search2008top-k clustered-graph ranking q2semantic queries scalability structure query search The increasing amount of data on the Semantic Web offers opportunities for semantic search. However, formal query hinders the casual users in expressing their information need as they might be not familiar with the query's syntax or the underlying ontology. Because keyword interfaces are easier to handle for casual users, many approaches aim to translate keywords to formal queries. However, these approaches yet feature only very basic query ranking and do not scale to large repositories. We tackle the scalability problem by proposing a novel clustered-graph structure that corresponds to only a summary of the original ontology. The so reduced data space is then used in the exploration for the computation of top-k queries. Additionally, we adopt several mechanisms for query ranking, which can consider many factors such as the query length and the relevance of ontology elements w.r.t. the query. Our experimental results performed against our implemented system Q2Semantic show that we achieve good performance on many datasets of different sizes.