A Study on the Use of Stemming for Monolingual Ad-Hoc Portuguese Information Retrieval

  • Viviane Moreira Orengo
  • Luciana S. Buriol
  • Alexandre Ramos Coelho
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4730)


For UFRGS’s first participation in CLEF our goal was to compare the performance of heavier and lighter stemming strategies using the Portuguese data collections for monolingual Ad-hoc retrieval. The results show that the safest strategy was to use the lighter alternative (reducing plural forms only). On a query-by-query analysis, full stemming achieved the highest improvement but also the biggest decrease in performance when compared to no stemming. In addition, statistical tests showed that the only significant improvement in terms of mean average precision, precision at ten and number of relevant retrieved was achieved by our lighter stemmer.


Information Retrieval Relevant Document Average Precision Portuguese Version Retrieval Experiment 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. 1.
    Cunha, C., Lindley-Cintra, L.: Nova Gramática do Português Contemporâneo. Rio de Janeiro: Nova Fronteira (in Portuguese, 1985)Google Scholar
  2. 2.
    Hull, D.: Using Statistical Testing in the Evaluation of Retrieval experiments. In: ACM SIGIR Conference on Research and Development in Information Retrieval, pp. 329-338. Pittsburgh (1993)Google Scholar
  3. 3.
    Macambira, J.R.: A Estrutura Morfo-Sintática do Português. São Paulo, Brazil: Ed. Pioneira (in Portuguese, 1999)Google Scholar
  4. 4.
    Orengo, V.M., Huyck, C.R.: A Stemming Algorithm for the Portuguese Language. In: 8th International Symposium on String Processing and Information Retrieval (SPIRE). Laguna de San Raphael, Chile, pp. 183–193 (2001)Google Scholar
  5. 5.
    SMART Information Retrieval System,
  6. 6.

Copyright information

© Springer-Verlag Berlin Heidelberg 2007

Authors and Affiliations

  • Viviane Moreira Orengo
    • 1
  • Luciana S. Buriol
    • 1
  • Alexandre Ramos Coelho
    • 1
  1. 1.UFRGS, Instituto de Informática, Porto AlegreBrazil

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