In this paper, we address the problem of cooperative query answering on Semantic Web Databases (SWDBs) in order to overcome the problem of empty or unsatisfactory answers. While most existing approaches propose an automatic relaxation process based on RDF-S entailment, our proposition consists in endowing SWDB query languages with relaxation and approximation operators. The main interest of this approach is that the relaxation process can be finely controlled by the user or implicitly by the system. Experiments on real data are conducted to evaluate (1) the scalability of the proposed operators and (2) the interest of the similarity measure defined to rank the alternative answers.
展开▼
