Reranking Hypotheses of Machine-Translated Queries for Cross-Lingual Information Retrieval

Machine Translation (MT) systems employed to translate queries for Cross-Lingual Information Retrieval typically produce a single translation with maximum translation quality. This, however, might not be optimal with respect to retrieval quality and other translation variants might lead to better retrieval results. In this paper, we explore a method using multiple translations produced by an MT system, which are reranked using a supervised machine-learning method trained to directly optimize retrieval quality. We experiment with various types of features and the results obtained on the medical-domain test collection from the CLEF eHealth Lab series show significant improvement of retrieval quality compared to a system using single translation provided by MT.