Expanding Queries with Term and Phrase Translations in Patent Retrieval

Abstract

Patent retrieval is a branch of Information Retrieval (IR) that aims to enable the challenging task of retrieving highly technical and often complicated patents. Typically, patent granting bodies translate patents into several major foreign languages, so that language boundaries do not hinder their accessibility. Given such multilingual patent collections, we posit that the patent translations can be exploited for facilitating patent retrieval. Specifically, we focus on the translation of patent queries from German and French, the morphology of which poses an extra challenge to retrieval. We compare two translation approaches that expand the query with (i) translated terms and (ii) translated phrases. Experimental evaluation on a standard CLEF-IP European Patent Office dataset reveals a novel finding: phrase translation may be more suited to French, and term translation may be more suited to German. We trace this finding to language morphology, and we conclude that tailoring the query translation per language can lead to improved results in patent retrieval.