Tag Cloud Query Builder for Semantic Web Knowledge Bases

As the number of available Semantic Web triples continues to grow, the need for effective tools to browse large Semantic Web Knowledge Bases (SWKBs) becomes more and more evident. In this paper, we present the novel Tag Cloud Query Builder (TCQB), which allows users to visually browse ontologies and then generate queries by connecting browsing chains to a query graph. TCQB utilizes font size and text color in the tag cloud to convey the contextual data frequency and click frequency of each concept, and enables users to quickly grasp the usage pattern of unfamiliar ontologies and the domain of the SWKB. To build a query, the user can store historical browsing chains in a query cart, which is visualized by a query graph, and then link different chains by specifying the instance nodes in these chains are equivalent or adding filters that involves two literal nodes.