A Study on the Use of Stemming for Monolingual Ad-Hoc Portuguese Information Retrieval
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.
KeywordsInformation Retrieval Relevant Document Average Precision Portuguese Version Retrieval Experiment
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- 1.Cunha, C., Lindley-Cintra, L.: Nova Gramática do Português Contemporâneo. Rio de Janeiro: Nova Fronteira (in Portuguese, 1985)Google Scholar
- 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.Macambira, J.R.: A Estrutura Morfo-Sintática do Português. São Paulo, Brazil: Ed. Pioneira (in Portuguese, 1999)Google Scholar
- 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.SMART Information Retrieval System, ftp://ftp.cs.cornell.edu/pub/smart/