A German Natural Language Interface for Semantic Search

Semantic data is the key for an efficient information retrieval. It relies on a well-defined structure and enables automated processing. Therefore, more and more ontologies are specified, extended and interlinked. By now, only the query language SPARQL provides a precise access to semantic data. Since most common users are overstrained in formulating queries, which satisfy the structure of semantic data, more search-interface approaches emerge aiming at good usability and correct answers. We implemented a Natural Language Interface (NLI), that answers questions formulated in German natural language. In order to query the domain ontology, the user query is translated into SPARQL first. Since domain-ontology resources are required for the SPARQL-query formulation, this paper introduces an approach for the identification of resources in user query. We show a path-based identification of semantically similar resources and a similarity measure. After running 100 test questions, our system achieves a precision and recall of 66%.