Working towards a Greek-English cross-language passage retrieval system for question-answering

In this thesis, we present a set of experiments towards a cross-language Greek-English Question-Answering (QA) system. After exploring previous work done both in monolingual and cross-lingual QA, we have applied the common "question reformulation" strategy used in monolingual systems along with different translation strategies and evaluated the results with the TREC question set. We have mainly focused on the passage retrieval component. 24,2% of the documents retrieved for all questions contained a correct answer for the cross language component (compared to 38,3% for the monolingual component) and for 61,2% of the questions used we have obtained at least one document that contained the correct answer (compared to 91% for the monolingiual component