This paper describes the fourth participation of IR-n system (Alicante University) at CLEF conferences. At present conference, we have modified the similarity measure and the query expansion model. Concerning the similarity measure, we use the normalization based on the number of words for each one of the passages. Finally, we test two different approaches for query expansion: the first one is based on documents and the second one is based on passages.
Fernando Llopis, Rafael Muñoz, Rafael M. Te