The PUCRS NLP-Group Participation in CLEF2006: Information Retrieval Based on Linguistic Resources

  • Marco Gonzalez
  • Vera Lúcia Strube de Lima
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4730)


This paper presents the 2006 participation of the PUCRS NLP-Group in the CLEF Monolingual Ad Hoc Task for Portuguese. We took part in this campaign using the TR+ Model, which is based on nominalization, binary lexical relations (BLR), Boolean queries, and the evidence concept. Our alternative strategy for lexical normalization, the nominalization, is to transform a word (adjective, verb, or adverb) into a semantically corresponding noun. BLRs identify relationships between nominalized terms and capture phrasal cohesion mechanisms, like those between subject and predicate, subject and object (direct or indirect), noun and adjective or verb and adverb. In our strategy, an index unit (a descriptor) may be a single term or a BLR, and we adopt the evidence concept: the descriptor weighting depends on the occurrence of phrasal cohesion mechanisms, besides depending on frequency of occurrence. We describe these features, which implement lexical normalization and term dependence in an information retrieval system based on linguistic resources.


Search engine information retrieval evaluation lexical normalization term dependence 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2007

Authors and Affiliations

  • Marco Gonzalez
    • 1
  • Vera Lúcia Strube de Lima
    • 1
  1. 1.Grupo PLN – Faculdade de Informática – PUCRS, Av. Ipiranga, 6681 – Prédio 16 - PPGCC, 90619-900 Porto AlegreBrazil

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