Bridging structured and unstructured data via hybrid semantic search and interactive ontology-enhanced query formulation

In this paper, we identify the problems of current semantic and hybrid search systems, which seek to bridge structure and unstructured data, and propose solutions. We introduce a novel input mechanism for hybrid semantic search that combines the clean and concise input mechanisms of keyword-based search engines with the expressiveness of the input mechanisms provided by semantic search engines. This interactive input mechanism can be used to formulate ontology-aware search queries without prior knowledge of the ontology. Furthermore, we propose a system architecture for automatically fetching relevant unstructured data, complementing structured data stored in a Knowledge Base, to create a combined index. This combined index can be used to conduct hybrid semantic searches which leverage information from structured and unstructured sources. We present the reference implementation Hybrid Semantic Search System ( \(HS^3\) ), which uses the combined index to put hybrid semantic search into practice and implements the interactive ontology-enhanced keyword-based input mechanism. For demonstration purpose, we apply \(HS^3\) to the tourism domain. We present performance test results and the results of a user evaluation. Finally, we provide instructions on how to apply \(HS^3\) to arbitrary domains.