Answer Translation: An Alternative Approach to Cross-Lingual Question Answering

We approach cross-lingual question answering by using a mono-lingual QA system for the source language and by translating resulting answers into the target language. As far as we are aware, this is the first cross-lingual QA system in the history of CLEF that uses this method—almost without exception, cross-lingual QA systems use translation of the question or query terms instead. We demonstrate the feasibility of our alternative approach by using a mono-lingual QA system for English, and translating answers and finding appropriate documents in Italian and Dutch. For factoid and definition questions, we achieve overall accuracy scores ranging from 13% (EN→NL) to 17% (EN→IT) and lenient accuracy figures from 19% (EN→NL) to 25% (EN→IT). The advantage of this strategy to cross-lingual QA is that translation of answers is easier than translating questions—the disadvantage is that answers might be missing from the source corpus and additional effort is required for finding supporting documents of the target language.