Document (#34952)

Author
Fautsch, C.
Savoy, J.
Title
Algorithmic stemmers or morphological analysis? : an evaluation
Source
Journal of the American Society for Information Science and Technology. 60(2009) no.8, S.1616-1624
Year
2009
Abstract
It is important in information retrieval (IR), information extraction, or classification tasks that morphologically related forms are conflated under the same stem (using stemmer) or lemma (using morphological analyzer). To achieve this for the English language, algorithmic stemming or various morphological analysis approaches have been suggested. Based on Cross-Language Evaluation Forum test collections containing 284 queries and various IR models, this article evaluates these word-normalization proposals. Stemming improves the mean average precision significantly by around 7% while performance differences are not significant when comparing various algorithmic stemmers or algorithmic stemmers and morphological analysis. Accounting for thesaurus class numbers during indexing does not modify overall retrieval performances. Finally, we demonstrate that including a stop word list, even one containing only around 10 terms, might significantly improve retrieval performance, depending on the IR model.
Theme
Computerlinguistik

Similar documents (author)

  1. Savoy, J.: Stemming of French words based on grammatical categories (1993) 5.21
    5.2066784 = sum of:
      5.2066784 = weight(author_txt:savoy in 4650) [ClassicSimilarity], result of:
        5.2066784 = fieldWeight in 4650, product of:
          1.0 = tf(freq=1.0), with freq of:
            1.0 = termFreq=1.0
          8.330686 = idf(docFreq=27, maxDocs=42740)
          0.625 = fieldNorm(doc=4650)
    
  2. Savoy, J.: Effectiveness of information retrieval systems used in a hypertext environment (1993) 5.21
    5.2066784 = sum of:
      5.2066784 = weight(author_txt:savoy in 6511) [ClassicSimilarity], result of:
        5.2066784 = fieldWeight in 6511, product of:
          1.0 = tf(freq=1.0), with freq of:
            1.0 = termFreq=1.0
          8.330686 = idf(docFreq=27, maxDocs=42740)
          0.625 = fieldNorm(doc=6511)
    
  3. Savoy, J.: ¬A learning scheme for information retrieval in hypertext (1994) 5.21
    5.2066784 = sum of:
      5.2066784 = weight(author_txt:savoy in 7292) [ClassicSimilarity], result of:
        5.2066784 = fieldWeight in 7292, product of:
          1.0 = tf(freq=1.0), with freq of:
            1.0 = termFreq=1.0
          8.330686 = idf(docFreq=27, maxDocs=42740)
          0.625 = fieldNorm(doc=7292)
    
  4. Savoy, J.: Bayesian inference networks and spreading activation in hypertext systems (1992) 5.21
    5.2066784 = sum of:
      5.2066784 = weight(author_txt:savoy in 261) [ClassicSimilarity], result of:
        5.2066784 = fieldWeight in 261, product of:
          1.0 = tf(freq=1.0), with freq of:
            1.0 = termFreq=1.0
          8.330686 = idf(docFreq=27, maxDocs=42740)
          0.625 = fieldNorm(doc=261)
    
  5. Savoy, J.: Searching information in legal hypertext systems (1993/94) 5.21
    5.2066784 = sum of:
      5.2066784 = weight(author_txt:savoy in 826) [ClassicSimilarity], result of:
        5.2066784 = fieldWeight in 826, product of:
          1.0 = tf(freq=1.0), with freq of:
            1.0 = termFreq=1.0
          8.330686 = idf(docFreq=27, maxDocs=42740)
          0.625 = fieldNorm(doc=826)
    

Similar documents (content)

  1. Kettunen, K.; Kunttu, T.; Järvelin, K.: To stem or lemmatize a highly inflectional language in a probabilistic IR environment? (2005) 0.42
    0.42322388 = sum of:
      0.42322388 = product of:
        1.0580597 = sum of:
          0.012273533 = weight(abstract_txt:using in 396) [ClassicSimilarity], result of:
            0.012273533 = score(doc=396,freq=2.0), product of:
              0.045609 = queryWeight, product of:
                3.4794931 = idf(docFreq=3580, maxDocs=42740)
                0.013107944 = queryNorm
              0.26910332 = fieldWeight in 396, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                3.4794931 = idf(docFreq=3580, maxDocs=42740)
                0.0546875 = fieldNorm(doc=396)
          0.12686771 = weight(abstract_txt:stem in 396) [ClassicSimilarity], result of:
            0.12686771 = score(doc=396,freq=5.0), product of:
              0.12656537 = queryWeight, product of:
                1.1779237 = boost
                8.197155 = idf(docFreq=31, maxDocs=42740)
                0.013107944 = queryNorm
              1.0023888 = fieldWeight in 396, product of:
                2.236068 = tf(freq=5.0), with freq of:
                  5.0 = termFreq=5.0
                8.197155 = idf(docFreq=31, maxDocs=42740)
                0.0546875 = fieldNorm(doc=396)
          0.030392181 = weight(abstract_txt:language in 396) [ClassicSimilarity], result of:
            0.030392181 = score(doc=396,freq=4.0), product of:
              0.06625755 = queryWeight, product of:
                1.2052923 = boost
                4.1938066 = idf(docFreq=1752, maxDocs=42740)
                0.013107944 = queryNorm
              0.45869762 = fieldWeight in 396, product of:
                2.0 = tf(freq=4.0), with freq of:
                  4.0 = termFreq=4.0
                4.1938066 = idf(docFreq=1752, maxDocs=42740)
                0.0546875 = fieldNorm(doc=396)
          0.018683126 = weight(abstract_txt:evaluation in 396) [ClassicSimilarity], result of:
            0.018683126 = score(doc=396,freq=1.0), product of:
              0.07604089 = queryWeight, product of:
                1.2912142 = boost
                4.492771 = idf(docFreq=1299, maxDocs=42740)
                0.013107944 = queryNorm
              0.24569842 = fieldWeight in 396, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                4.492771 = idf(docFreq=1299, maxDocs=42740)
                0.0546875 = fieldNorm(doc=396)
          0.1126247 = weight(abstract_txt:stemmer in 396) [ClassicSimilarity], result of:
            0.1126247 = score(doc=396,freq=2.0), product of:
              0.15866578 = queryWeight, product of:
                1.318868 = boost
                9.177984 = idf(docFreq=11, maxDocs=42740)
                0.013107944 = queryNorm
              0.7098235 = fieldWeight in 396, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                9.177984 = idf(docFreq=11, maxDocs=42740)
                0.0546875 = fieldNorm(doc=396)
          0.081924215 = weight(abstract_txt:morphologically in 396) [ClassicSimilarity], result of:
            0.081924215 = score(doc=396,freq=1.0), product of:
              0.16168846 = queryWeight, product of:
                1.3313714 = boost
                9.264996 = idf(docFreq=10, maxDocs=42740)
                0.013107944 = queryNorm
              0.5066794 = fieldWeight in 396, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                9.264996 = idf(docFreq=10, maxDocs=42740)
                0.0546875 = fieldNorm(doc=396)
          0.020616667 = weight(abstract_txt:performance in 396) [ClassicSimilarity], result of:
            0.020616667 = score(doc=396,freq=1.0), product of:
              0.081200704 = queryWeight, product of:
                1.3343035 = boost
                4.6426997 = idf(docFreq=1118, maxDocs=42740)
                0.013107944 = queryNorm
              0.25389764 = fieldWeight in 396, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                4.6426997 = idf(docFreq=1118, maxDocs=42740)
                0.0546875 = fieldNorm(doc=396)
          0.01285384 = weight(abstract_txt:retrieval in 396) [ClassicSimilarity], result of:
            0.01285384 = score(doc=396,freq=1.0), product of:
              0.06783698 = queryWeight, product of:
                1.4936663 = boost
                3.4648013 = idf(docFreq=3633, maxDocs=42740)
                0.013107944 = queryNorm
              0.18948132 = fieldWeight in 396, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                3.4648013 = idf(docFreq=3633, maxDocs=42740)
                0.0546875 = fieldNorm(doc=396)
          0.120152466 = weight(abstract_txt:stemming in 396) [ClassicSimilarity], result of:
            0.120152466 = score(doc=396,freq=2.0), product of:
              0.20871772 = queryWeight, product of:
                2.1392148 = boost
                7.4433827 = idf(docFreq=67, maxDocs=42740)
                0.013107944 = queryNorm
              0.5756697 = fieldWeight in 396, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                7.4433827 = idf(docFreq=67, maxDocs=42740)
                0.0546875 = fieldNorm(doc=396)
          0.5216713 = weight(abstract_txt:morphological in 396) [ClassicSimilarity], result of:
            0.5216713 = score(doc=396,freq=6.0), product of:
              0.48525685 = queryWeight, product of:
                4.612916 = boost
                8.025305 = idf(docFreq=37, maxDocs=42740)
                0.013107944 = queryNorm
              1.0750415 = fieldWeight in 396, product of:
                2.4494898 = tf(freq=6.0), with freq of:
                  6.0 = termFreq=6.0
                8.025305 = idf(docFreq=37, maxDocs=42740)
                0.0546875 = fieldNorm(doc=396)
        0.4 = coord(10/25)
    
  2. Snajder, J.; Dalbelo Basic, B.D.; Tadic, M.: Automatic acquisition of inflectional lexica for morphological normalisation (2008) 0.37
    0.36737496 = sum of:
      0.36737496 = product of:
        1.1480467 = sum of:
          0.030700738 = weight(abstract_txt:language in 4911) [ClassicSimilarity], result of:
            0.030700738 = score(doc=4911,freq=2.0), product of:
              0.06625755 = queryWeight, product of:
                1.2052923 = boost
                4.1938066 = idf(docFreq=1752, maxDocs=42740)
                0.013107944 = queryNorm
              0.46335456 = fieldWeight in 4911, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                4.1938066 = idf(docFreq=1752, maxDocs=42740)
                0.078125 = fieldNorm(doc=4911)
          0.1170346 = weight(abstract_txt:morphologically in 4911) [ClassicSimilarity], result of:
            0.1170346 = score(doc=4911,freq=1.0), product of:
              0.16168846 = queryWeight, product of:
                1.3313714 = boost
                9.264996 = idf(docFreq=10, maxDocs=42740)
                0.013107944 = queryNorm
              0.7238278 = fieldWeight in 4911, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                9.264996 = idf(docFreq=10, maxDocs=42740)
                0.078125 = fieldNorm(doc=4911)
          0.029452382 = weight(abstract_txt:performance in 4911) [ClassicSimilarity], result of:
            0.029452382 = score(doc=4911,freq=1.0), product of:
              0.081200704 = queryWeight, product of:
                1.3343035 = boost
                4.6426997 = idf(docFreq=1118, maxDocs=42740)
                0.013107944 = queryNorm
              0.36271092 = fieldWeight in 4911, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                4.6426997 = idf(docFreq=1118, maxDocs=42740)
                0.078125 = fieldNorm(doc=4911)
          0.01836263 = weight(abstract_txt:retrieval in 4911) [ClassicSimilarity], result of:
            0.01836263 = score(doc=4911,freq=1.0), product of:
              0.06783698 = queryWeight, product of:
                1.4936663 = boost
                3.4648013 = idf(docFreq=3633, maxDocs=42740)
                0.013107944 = queryNorm
              0.2706876 = fieldWeight in 4911, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                3.4648013 = idf(docFreq=3633, maxDocs=42740)
                0.078125 = fieldNorm(doc=4911)
          0.04775576 = weight(abstract_txt:word in 4911) [ClassicSimilarity], result of:
            0.04775576 = score(doc=4911,freq=1.0), product of:
              0.11207189 = queryWeight, product of:
                1.567556 = boost
                5.4543004 = idf(docFreq=496, maxDocs=42740)
                0.013107944 = queryNorm
              0.4261172 = fieldWeight in 4911, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                5.4543004 = idf(docFreq=496, maxDocs=42740)
                0.078125 = fieldNorm(doc=4911)
          0.038123608 = weight(abstract_txt:various in 4911) [ClassicSimilarity], result of:
            0.038123608 = score(doc=4911,freq=1.0), product of:
              0.11040089 = queryWeight, product of:
                1.9054898 = boost
                4.4200926 = idf(docFreq=1397, maxDocs=42740)
                0.013107944 = queryNorm
              0.34531975 = fieldWeight in 4911, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                4.4200926 = idf(docFreq=1397, maxDocs=42740)
                0.078125 = fieldNorm(doc=4911)
          0.121372335 = weight(abstract_txt:stemming in 4911) [ClassicSimilarity], result of:
            0.121372335 = score(doc=4911,freq=1.0), product of:
              0.20871772 = queryWeight, product of:
                2.1392148 = boost
                7.4433827 = idf(docFreq=67, maxDocs=42740)
                0.013107944 = queryNorm
              0.5815143 = fieldWeight in 4911, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                7.4433827 = idf(docFreq=67, maxDocs=42740)
                0.078125 = fieldNorm(doc=4911)
          0.7452446 = weight(abstract_txt:morphological in 4911) [ClassicSimilarity], result of:
            0.7452446 = score(doc=4911,freq=6.0), product of:
              0.48525685 = queryWeight, product of:
                4.612916 = boost
                8.025305 = idf(docFreq=37, maxDocs=42740)
                0.013107944 = queryNorm
              1.5357735 = fieldWeight in 4911, product of:
                2.4494898 = tf(freq=6.0), with freq of:
                  6.0 = termFreq=6.0
                8.025305 = idf(docFreq=37, maxDocs=42740)
                0.078125 = fieldNorm(doc=4911)
        0.32 = coord(8/25)
    
  3. Kraaij, W.; Pohlmann, R.: Evaluation of a Dutch stemming algorithm (1995) 0.35
    0.35035178 = sum of:
      0.35035178 = product of:
        0.97319937 = sum of:
          0.0123981405 = weight(abstract_txt:using in 5867) [ClassicSimilarity], result of:
            0.0123981405 = score(doc=5867,freq=1.0), product of:
              0.045609 = queryWeight, product of:
                3.4794931 = idf(docFreq=3580, maxDocs=42740)
                0.013107944 = queryNorm
              0.2718354 = fieldWeight in 5867, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                3.4794931 = idf(docFreq=3580, maxDocs=42740)
                0.078125 = fieldNorm(doc=5867)
          0.08105281 = weight(abstract_txt:stem in 5867) [ClassicSimilarity], result of:
            0.08105281 = score(doc=5867,freq=1.0), product of:
              0.12656537 = queryWeight, product of:
                1.1779237 = boost
                8.197155 = idf(docFreq=31, maxDocs=42740)
                0.013107944 = queryNorm
              0.64040273 = fieldWeight in 5867, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                8.197155 = idf(docFreq=31, maxDocs=42740)
                0.078125 = fieldNorm(doc=5867)
          0.02669018 = weight(abstract_txt:evaluation in 5867) [ClassicSimilarity], result of:
            0.02669018 = score(doc=5867,freq=1.0), product of:
              0.07604089 = queryWeight, product of:
                1.2912142 = boost
                4.492771 = idf(docFreq=1299, maxDocs=42740)
                0.013107944 = queryNorm
              0.35099775 = fieldWeight in 5867, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                4.492771 = idf(docFreq=1299, maxDocs=42740)
                0.078125 = fieldNorm(doc=5867)
          0.16089243 = weight(abstract_txt:stemmer in 5867) [ClassicSimilarity], result of:
            0.16089243 = score(doc=5867,freq=2.0), product of:
              0.15866578 = queryWeight, product of:
                1.318868 = boost
                9.177984 = idf(docFreq=11, maxDocs=42740)
                0.013107944 = queryNorm
              1.0140336 = fieldWeight in 5867, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                9.177984 = idf(docFreq=11, maxDocs=42740)
                0.078125 = fieldNorm(doc=5867)
          0.1170346 = weight(abstract_txt:morphologically in 5867) [ClassicSimilarity], result of:
            0.1170346 = score(doc=5867,freq=1.0), product of:
              0.16168846 = queryWeight, product of:
                1.3313714 = boost
                9.264996 = idf(docFreq=10, maxDocs=42740)
                0.013107944 = queryNorm
              0.7238278 = fieldWeight in 5867, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                9.264996 = idf(docFreq=10, maxDocs=42740)
                0.078125 = fieldNorm(doc=5867)
          0.01836263 = weight(abstract_txt:retrieval in 5867) [ClassicSimilarity], result of:
            0.01836263 = score(doc=5867,freq=1.0), product of:
              0.06783698 = queryWeight, product of:
                1.4936663 = boost
                3.4648013 = idf(docFreq=3633, maxDocs=42740)
                0.013107944 = queryNorm
              0.2706876 = fieldWeight in 5867, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                3.4648013 = idf(docFreq=3633, maxDocs=42740)
                0.078125 = fieldNorm(doc=5867)
          0.022151284 = weight(abstract_txt:analysis in 5867) [ClassicSimilarity], result of:
            0.022151284 = score(doc=5867,freq=1.0), product of:
              0.07687336 = queryWeight, product of:
                1.5900409 = boost
                3.6883576 = idf(docFreq=2905, maxDocs=42740)
                0.013107944 = queryNorm
              0.28815293 = fieldWeight in 5867, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                3.6883576 = idf(docFreq=2905, maxDocs=42740)
                0.078125 = fieldNorm(doc=5867)
          0.21022305 = weight(abstract_txt:stemming in 5867) [ClassicSimilarity], result of:
            0.21022305 = score(doc=5867,freq=3.0), product of:
              0.20871772 = queryWeight, product of:
                2.1392148 = boost
                7.4433827 = idf(docFreq=67, maxDocs=42740)
                0.013107944 = queryNorm
              1.0072123 = fieldWeight in 5867, product of:
                1.7320508 = tf(freq=3.0), with freq of:
                  3.0 = termFreq=3.0
                7.4433827 = idf(docFreq=67, maxDocs=42740)
                0.078125 = fieldNorm(doc=5867)
          0.32439423 = weight(abstract_txt:stemmers in 5867) [ClassicSimilarity], result of:
            0.32439423 = score(doc=5867,freq=1.0), product of:
              0.46014214 = queryWeight, product of:
                3.8901498 = boost
                9.023833 = idf(docFreq=13, maxDocs=42740)
                0.013107944 = queryNorm
              0.704987 = fieldWeight in 5867, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                9.023833 = idf(docFreq=13, maxDocs=42740)
                0.078125 = fieldNorm(doc=5867)
        0.36 = coord(9/25)
    
  4. Dolamic, L.; Savoy, J.: Indexing and searching strategies for the Russian language (2009) 0.24
    0.24314138 = sum of:
      0.24314138 = product of:
        0.86836207 = sum of:
          0.030080456 = weight(abstract_txt:language in 302) [ClassicSimilarity], result of:
            0.030080456 = score(doc=302,freq=3.0), product of:
              0.06625755 = queryWeight, product of:
                1.2052923 = boost
                4.1938066 = idf(docFreq=1752, maxDocs=42740)
                0.013107944 = queryNorm
              0.45399287 = fieldWeight in 302, product of:
                1.7320508 = tf(freq=3.0), with freq of:
                  3.0 = termFreq=3.0
                4.1938066 = idf(docFreq=1752, maxDocs=42740)
                0.0625 = fieldNorm(doc=302)
          0.12871394 = weight(abstract_txt:stemmer in 302) [ClassicSimilarity], result of:
            0.12871394 = score(doc=302,freq=2.0), product of:
              0.15866578 = queryWeight, product of:
                1.318868 = boost
                9.177984 = idf(docFreq=11, maxDocs=42740)
                0.013107944 = queryNorm
              0.81122684 = fieldWeight in 302, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                9.177984 = idf(docFreq=11, maxDocs=42740)
                0.0625 = fieldNorm(doc=302)
          0.040810414 = weight(abstract_txt:performance in 302) [ClassicSimilarity], result of:
            0.040810414 = score(doc=302,freq=3.0), product of:
              0.081200704 = queryWeight, product of:
                1.3343035 = boost
                4.6426997 = idf(docFreq=1118, maxDocs=42740)
                0.013107944 = queryNorm
              0.50258696 = fieldWeight in 302, product of:
                1.7320508 = tf(freq=3.0), with freq of:
                  3.0 = termFreq=3.0
                4.6426997 = idf(docFreq=1118, maxDocs=42740)
                0.0625 = fieldNorm(doc=302)
          0.020774944 = weight(abstract_txt:retrieval in 302) [ClassicSimilarity], result of:
            0.020774944 = score(doc=302,freq=2.0), product of:
              0.06783698 = queryWeight, product of:
                1.4936663 = boost
                3.4648013 = idf(docFreq=3633, maxDocs=42740)
                0.013107944 = queryNorm
              0.30624807 = fieldWeight in 302, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                3.4648013 = idf(docFreq=3633, maxDocs=42740)
                0.0625 = fieldNorm(doc=302)
          0.043131936 = weight(abstract_txt:various in 302) [ClassicSimilarity], result of:
            0.043131936 = score(doc=302,freq=2.0), product of:
              0.11040089 = queryWeight, product of:
                1.9054898 = boost
                4.4200926 = idf(docFreq=1397, maxDocs=42740)
                0.013107944 = queryNorm
              0.39068466 = fieldWeight in 302, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                4.4200926 = idf(docFreq=1397, maxDocs=42740)
                0.0625 = fieldNorm(doc=302)
          0.23784024 = weight(abstract_txt:stemming in 302) [ClassicSimilarity], result of:
            0.23784024 = score(doc=302,freq=6.0), product of:
              0.20871772 = queryWeight, product of:
                2.1392148 = boost
                7.4433827 = idf(docFreq=67, maxDocs=42740)
                0.013107944 = queryNorm
              1.1395307 = fieldWeight in 302, product of:
                2.4494898 = tf(freq=6.0), with freq of:
                  6.0 = termFreq=6.0
                7.4433827 = idf(docFreq=67, maxDocs=42740)
                0.0625 = fieldNorm(doc=302)
          0.36701015 = weight(abstract_txt:stemmers in 302) [ClassicSimilarity], result of:
            0.36701015 = score(doc=302,freq=2.0), product of:
              0.46014214 = queryWeight, product of:
                3.8901498 = boost
                9.023833 = idf(docFreq=13, maxDocs=42740)
                0.013107944 = queryNorm
              0.7976017 = fieldWeight in 302, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                9.023833 = idf(docFreq=13, maxDocs=42740)
                0.0625 = fieldNorm(doc=302)
        0.28 = coord(7/25)
    
  5. Flores, F.N.; Moreira, V.P.: Assessing the impact of stemming accuracy on information retrieval : a multilingual perspective (2016) 0.23
    0.22596142 = sum of:
      0.22596142 = product of:
        0.9415059 = sum of:
          0.08105281 = weight(abstract_txt:stem in 5188) [ClassicSimilarity], result of:
            0.08105281 = score(doc=5188,freq=1.0), product of:
              0.12656537 = queryWeight, product of:
                1.1779237 = boost
                8.197155 = idf(docFreq=31, maxDocs=42740)
                0.013107944 = queryNorm
              0.64040273 = fieldWeight in 5188, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                8.197155 = idf(docFreq=31, maxDocs=42740)
                0.078125 = fieldNorm(doc=5188)
          0.041060086 = weight(abstract_txt:retrieval in 5188) [ClassicSimilarity], result of:
            0.041060086 = score(doc=5188,freq=5.0), product of:
              0.06783698 = queryWeight, product of:
                1.4936663 = boost
                3.4648013 = idf(docFreq=3633, maxDocs=42740)
                0.013107944 = queryNorm
              0.60527587 = fieldWeight in 5188, product of:
                2.236068 = tf(freq=5.0), with freq of:
                  5.0 = termFreq=5.0
                3.4648013 = idf(docFreq=3633, maxDocs=42740)
                0.078125 = fieldNorm(doc=5188)
          0.04775576 = weight(abstract_txt:word in 5188) [ClassicSimilarity], result of:
            0.04775576 = score(doc=5188,freq=1.0), product of:
              0.11207189 = queryWeight, product of:
                1.567556 = boost
                5.4543004 = idf(docFreq=496, maxDocs=42740)
                0.013107944 = queryNorm
              0.4261172 = fieldWeight in 5188, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                5.4543004 = idf(docFreq=496, maxDocs=42740)
                0.078125 = fieldNorm(doc=5188)
          0.038123608 = weight(abstract_txt:various in 5188) [ClassicSimilarity], result of:
            0.038123608 = score(doc=5188,freq=1.0), product of:
              0.11040089 = queryWeight, product of:
                1.9054898 = boost
                4.4200926 = idf(docFreq=1397, maxDocs=42740)
                0.013107944 = queryNorm
              0.34531975 = fieldWeight in 5188, product of:
                1.0 = tf(freq=1.0), with freq of:
                  1.0 = termFreq=1.0
                4.4200926 = idf(docFreq=1397, maxDocs=42740)
                0.078125 = fieldNorm(doc=5188)
          0.17164639 = weight(abstract_txt:stemming in 5188) [ClassicSimilarity], result of:
            0.17164639 = score(doc=5188,freq=2.0), product of:
              0.20871772 = queryWeight, product of:
                2.1392148 = boost
                7.4433827 = idf(docFreq=67, maxDocs=42740)
                0.013107944 = queryNorm
              0.8223853 = fieldWeight in 5188, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                7.4433827 = idf(docFreq=67, maxDocs=42740)
                0.078125 = fieldNorm(doc=5188)
          0.56186724 = weight(abstract_txt:stemmers in 5188) [ClassicSimilarity], result of:
            0.56186724 = score(doc=5188,freq=3.0), product of:
              0.46014214 = queryWeight, product of:
                3.8901498 = boost
                9.023833 = idf(docFreq=13, maxDocs=42740)
                0.013107944 = queryNorm
              1.2210733 = fieldWeight in 5188, product of:
                1.7320508 = tf(freq=3.0), with freq of:
                  3.0 = termFreq=3.0
                9.023833 = idf(docFreq=13, maxDocs=42740)
                0.078125 = fieldNorm(doc=5188)
        0.24 = coord(6/25)