Chemnitz at CLEF 2009 Ad-Hoc TEL Task: Combining Different Retrieval Models and Addressing the Multilinguality

Jens Kürsten
2009 Conference and Labs of the Evaluation Forum  
In this paper we report our efforts for the participation in the CLEF 2009 Ad-Hoc TEL task. In our second participation we were able to test and evaluate a new feature of the Xtrieval framework, which was the accessibility of the three core retrieval engines Lucene, Lemur and Terrier. This year we submitted 24 experiments in total, 12 each for the monolingual and bilingual subtasks. We compared our baseline experiments to combined runs, where we used two different retrieval models, namely the
more » ... ctor space model (VSM) used in Lucene and the Bose-Einstein model for randomness (BB2) available in the Terrier framework. We found that an almost constant improvement in terms of mean average precision over all provided collections is achievable. Furthermore we tried to benefit from the multilingual contents of the collections by running combined multilingual experiments for both subtasks. The evaluation showed that the used approach achieves small improvements in the monolingual setting of the task. Unfortunately, we were not able to confirm this finding in the bilingual setting, where the multilingual experiments were outperformed by the standard bilingual runs, especially on the English target collection.
dblp:conf/clef/Kursten09 fatcat:gu6cnntlj5dc3b3oy7427rsjde