Does dictionary based bilingual retrieval work in a non-normalized index?

  • Authors:
  • Eija Airio;Kimmo Kettunen

  • Affiliations:
  • University of Tampere, Department of Information Studies, Kanslerinrinne 1, FIN-33014, Finland;University of Tampere, Department of Information Studies, Kanslerinrinne 1, FIN-33014, Finland

  • Venue:
  • Information Processing and Management: an International Journal
  • Year:
  • 2009

Quantified Score

Hi-index 0.00

Visualization

Abstract

Many operational IR indexes are non-normalized, i.e. no lemmatization or stemming techniques, etc. have been employed in indexing. This poses a challenge for dictionary-based cross-language retrieval (CLIR), because translations are mostly lemmas. In this study, we face the challenge of dictionary-based CLIR in a non-normalized index. We test two optional approaches: FCG (Frequent Case Generation) and s-gramming. The idea of FCG is to automatically generate the most frequent inflected forms for a given lemma. FCG has been tested in monolingual retrieval and has been shown to be a good method for inflected retrieval, especially for highly inflected languages. S-gramming is an approximate string matching technique (an extension of n-gramming). The language pairs in our tests were English-Finnish, English-Swedish, Swedish-Finnish and Finnish-Swedish. Both our approaches performed quite well, but the results varied depending on the language pair. S-gramming and FCG performed quite equally in all the other language pairs except Finnish-Swedish, where s-gramming outperformed FCG.