NTICR-4 Chinese, English Korean Cross Language Retrieval Experiments using PIRCS

In NTCIR-5 our focus is to see if web-assisted query expansion is useful, and to test an English-Korean bilingual dictionary. We participated in Chinese, Japanese, Korean and English monolingual retrieval using also web expansion for Chinese and English. We also performed Chinese-English, English-Chinese, English-Korean bilingual, and Chinese-Korean pivot bilingual CLIR. The query translation approach was employed. MT translation was combined with our web-based entity-oriented translation which translates named entities extracted from the original query as well as web-based expansion terms. For English-Korean, a dictionary translation method was also used. In general, monolingual retrieval results are about median, while cross-lingual runs (except Chinese-English) appear to be among the top results. For English-Korean, our bilingual dictionary translation by itself is not competitive, but when concatenated with web translation came to within 5% of MT with web translation. Using the web to expand a query before retrieval was not successful except for monolingual English and pivot bilingual Chinese-Korean retrieval