This paper describes the official runs of the Twenty-One group for CLEF-2000. The Twenty-One group participated in the monolingual, bilingual and multilingual tasks. The following new techniques are introduced in this paper. In the bilingual task we experimented with different methods to estimate translation probabilities. In the multilingual task we experimented with refinements on raw-score merging techniques and with a new relevance feedback algorithm that re-estimates both the model’s translation probabilities and the relevance weights. Finally, we performed preliminary experiments to exploit the web to generate translation probabilities and bilingual dictionaries, notably for English-Italian and English-Dutch.
['Djoerd Hiemstra', 'Wessel Kraaij', 'Ren ´ ee Pohlmann', 'Thijs Westerveld']
Twenty-One at CLEF-2000: Translation resources, merging strategies and relevance feedback