Query expansion from wikipedia and topic web crawler on clir

In this paper, we report various strategies for query expansion (QE) in the NTCIR-8 IR4QA subtask. We submit the results of twelve runs from the formal run, which include cross-language information retrieval from English to traditional Chinese, from English to simplified Chinese, and from English to Japanese in the official T-run, D-run and DN-run. Our approach uses Google translation and the Okapi BM25 pseudo relevance feedback as the basic retrieval system. We add more QE from Wikipedia and the result of QA analysis. In the additional runs, we use a topic web crawler to get more related web pages and to extract more keywords to act as candidates for QE