This paper presents a Query-and-Relax System (QaRS) designed to facilitate the exploitation of large knowledge bases. QaRS proposes a graphical interface to construct a SPARQL query and use different cooperative answering techniques. The proposed cooperative techniques help users in finding alternative answers when their queries fail or do not return the expected number of answers. The present demonstration includes three main relaxation strategies: (1)- automatic where the system automatically relaxes the query based on similarity measures, (2)- manual where the user can specify the conditions that can or cannot be relaxed as well as the tolerance values and (3)- interactive where QaRS computes the causes of the query failure as a set of Minimal Failing Subqueries (MFSs )a nd then the user chooses the relaxation operators according to these MFSs.
['Géraud Fokou', 'Stéphane Jean', 'Allel Hadjali', 'Mickaël Baron']
QaRS: A User-Friendly Graphical Tool for Semantic Query Design and Relaxation