The negative effect of machine translation on cross-lingual question answering

This paper presents a study of the negative effect of Machine Translation (MT) on the precision of Cross–Lingual Question Answering (CL–QA). For this research, a English–Spanish Question Answering (QA) system is used. Also, the sets of 200 official questions from CLEF 2004 and 2006 are used. The CL experimental evaluation using MT reveals that the precision of the system drops around 30% with regard to the monolingual Spanish task. Our main contribution consists on a taxonomy of the identified errors caused by using MT and how the errors can be overcome by using our proposals. An experimental evaluation proves that our approach performs better than MT tools, at the same time contributing to this CL–QA system being ranked first at English–Spanish QA CLEF 2006.This research has been partially funded by the Spanish Government under project CICyT number TIC2003-07158-C04-01 and by the European Commission under FP6 project QALL-ME number 033860