Spanish Monolingual Track: The Impact of Stemming on Retrieval

Most of the techniques used in Information Retrieval rely on the identification of terms from queries and documents, as much to carry out calculations based on the frequencies of these terms as to carry out comparisons between documents and queries. Terms coming from the same stem, either by morphological inflection or through derivation, can be presumed to have semantic proximity. The conflation of these words to a common form can produce improvements in retrieval. The stemming mechanisms used depend directly on each language. In this paper, a stemmer for Spanish and the tests conducted by applying it to the CLEF Spanish document collection are described, and the results are discussed.