Chinese Document Retrieval at Trec-6 1 Multilingual Document Retrieval in Trec

The TREC-6 conference was the fourth year in which document retrieval in a language other than English was carried out. In TREC-3, 4 groups participated in an ad hoc retrieval task on a collection of 208 Mbytes of Mexican newspaper text in the Spanish language. In TREC-4 there were 10 groups who participated, once again in an ad hoc document retrieval task on the same Mexican newspaper texts but with new topics. In TREC-5 there was a change of document corpus and new topics for the Spanish ad hoc retrieval task and a corpus of documents and topics to support ad hoc retrieval in the Chinese language was introduced for the rst time. In TREC-6 there was two tracks in which languages other than English were explored. In the Chinese track, a second set of topics were evaluated against the existing corpus. In the cross-lingual track experiments were conducted where queries in one language were used against a document corpus in another language. This report concentrates solely on the Chinese track. 2 Chinese Language In the Chinese language each character represents at least a complete syllable, rather than a letter as in other languages. Many characters are also single syllable words. The total number of characters is therefore quite large and somewhat ill-deened. A literate adult would typically recognise at least 5-6,000 characters. The various modern standards deene between 10-12,000 characters, although if early and ancient literature is included the number rises to approximately 100,000. Chinese is agglutinating { there is no space between consecutive characters, except perhaps, at the end of a sentence.