Cross-lingual English sentence retrieval considering syntactic structures of Japanese queries

This paper proposes a cross-lingual English sentence retrieval system for Japanese queries. The system retrieves English sentences exactly by considering dependency structures in both Japanese and English. It enables the system to reflect the user´s intention. We utilize a constraint on dependency structure of Japanese, i.e, any dependency is directed from left to right. By considering the constraint, our system can eliminate irrelevant sentences from search results. We conducted an experiment to evaluate the system. The results demonstrated that the rate of improvement of retrieval precision reached to 38.0% and the precision of filtering was 95.3%. Thus, we confirmed the effectiveness of our proposed system.