Document (#29394)

Author

Sparck Jones, K.

Title

Some thoughts on classification for retrieval

Source

Journal of documentation. 61(2005) no.5, S.571-581

Year

2005

Abstract

Purpose - This paper was originally published in 1970 (Journal of documentation. 26(1970), S.89-101), considered the suggestion that classifications for retrieval should be constructed automatically and raised some serious problems concerning the sorts of classification which were required, and the way in which formal classification theories should be exploited, given that a retrieval classification is required for a purpose. These difficulties had not been sufficiently considered, and the paper, therefore, aims to attempt an analysis of them, though no solutions of immediate application could be suggested. Design/methodology/approach - Starting with the illustrative proposition that a polythetic, multiple, unordered classification is required in automatic thesaurus construction, this is considered in the context of classification in general, where eight sorts of classification can be distinguished, each covering a range of class definitions and class-finding algorithms. Findings - Since there is generally no natural or best classification of a set of objects as such, the evaluation of alternative classifications requires either formal criteria of goodness of fit, or, if a classification is required for a purpose, a precise statement of that purpose. In any case a substantive theory of classification is needed, which does not exist; and, since sufficiently precise specifications of retrieval requirements are also lacking, the only currently available approach to automatic classification experiments for information retrieval is to do enough of them. Originality/value - Gives insights into the classification of material for information retrieval.

Footnote

Vgl. auch unter: http://www.emeraldinsight.com/10.1108/00220410510625796

Theme

Klassifikationssysteme im Online-Retrieval

Similar documents (author)

1. Sparck Jones, K.: Fashionable trends and feasible strategies in information management (1988) 5.30

   5.2995043 = sum of:
     5.2995043 = sum of:
       2.0662034 = weight(author_txt:jones in 817) [ClassicSimilarity], result of:
         2.0662034 = score(doc=817,freq=1.0), product of:
           0.5958338 = queryWeight, product of:
             6.9355025 = idf(docFreq=112, maxDocs=42740)
             0.085910685 = queryNorm
           3.4677513 = fieldWeight in 817, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             6.9355025 = idf(docFreq=112, maxDocs=42740)
             0.5 = fieldNorm(doc=817)
       3.2333007 = weight(author_txt:sparck in 817) [ClassicSimilarity], result of:
         3.2333007 = score(doc=817,freq=1.0), product of:
           0.80310774 = queryWeight, product of:
             1.1609789 = boost
             8.051972 = idf(docFreq=36, maxDocs=42740)
             0.085910685 = queryNorm
           4.025986 = fieldWeight in 817, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             8.051972 = idf(docFreq=36, maxDocs=42740)
             0.5 = fieldNorm(doc=817)
   

2. Sparck Jones, K.: Automatic classification (1976) 5.30

   5.2995043 = sum of:
     5.2995043 = sum of:
       2.0662034 = weight(author_txt:jones in 2908) [ClassicSimilarity], result of:
         2.0662034 = score(doc=2908,freq=1.0), product of:
           0.5958338 = queryWeight, product of:
             6.9355025 = idf(docFreq=112, maxDocs=42740)
             0.085910685 = queryNorm
           3.4677513 = fieldWeight in 2908, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             6.9355025 = idf(docFreq=112, maxDocs=42740)
             0.5 = fieldNorm(doc=2908)
       3.2333007 = weight(author_txt:sparck in 2908) [ClassicSimilarity], result of:
         3.2333007 = score(doc=2908,freq=1.0), product of:
           0.80310774 = queryWeight, product of:
             1.1609789 = boost
             8.051972 = idf(docFreq=36, maxDocs=42740)
             0.085910685 = queryNorm
           4.025986 = fieldWeight in 2908, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             8.051972 = idf(docFreq=36, maxDocs=42740)
             0.5 = fieldNorm(doc=2908)
   

3. Sparck Jones, K.: ¬The role of artificial intelligence in information retrieval (1991) 5.30

   5.2995043 = sum of:
     5.2995043 = sum of:
       2.0662034 = weight(author_txt:jones in 4811) [ClassicSimilarity], result of:
         2.0662034 = score(doc=4811,freq=1.0), product of:
           0.5958338 = queryWeight, product of:
             6.9355025 = idf(docFreq=112, maxDocs=42740)
             0.085910685 = queryNorm
           3.4677513 = fieldWeight in 4811, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             6.9355025 = idf(docFreq=112, maxDocs=42740)
             0.5 = fieldNorm(doc=4811)
       3.2333007 = weight(author_txt:sparck in 4811) [ClassicSimilarity], result of:
         3.2333007 = score(doc=4811,freq=1.0), product of:
           0.80310774 = queryWeight, product of:
             1.1609789 = boost
             8.051972 = idf(docFreq=36, maxDocs=42740)
             0.085910685 = queryNorm
           4.025986 = fieldWeight in 4811, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             8.051972 = idf(docFreq=36, maxDocs=42740)
             0.5 = fieldNorm(doc=4811)
   

4. Sparck Jones, K.: Automatic keyword classification for information retrieval (1971) 5.30

   5.2995043 = sum of:
     5.2995043 = sum of:
       2.0662034 = weight(author_txt:jones in 5176) [ClassicSimilarity], result of:
         2.0662034 = score(doc=5176,freq=1.0), product of:
           0.5958338 = queryWeight, product of:
             6.9355025 = idf(docFreq=112, maxDocs=42740)
             0.085910685 = queryNorm
           3.4677513 = fieldWeight in 5176, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             6.9355025 = idf(docFreq=112, maxDocs=42740)
             0.5 = fieldNorm(doc=5176)
       3.2333007 = weight(author_txt:sparck in 5176) [ClassicSimilarity], result of:
         3.2333007 = score(doc=5176,freq=1.0), product of:
           0.80310774 = queryWeight, product of:
             1.1609789 = boost
             8.051972 = idf(docFreq=36, maxDocs=42740)
             0.085910685 = queryNorm
           4.025986 = fieldWeight in 5176, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             8.051972 = idf(docFreq=36, maxDocs=42740)
             0.5 = fieldNorm(doc=5176)
   

5. Sparck Jones, K.: ¬A statistical interpretation of term specifity and its application in retrieval (1972) 5.30

   5.2995043 = sum of:
     5.2995043 = sum of:
       2.0662034 = weight(author_txt:jones in 5187) [ClassicSimilarity], result of:
         2.0662034 = score(doc=5187,freq=1.0), product of:
           0.5958338 = queryWeight, product of:
             6.9355025 = idf(docFreq=112, maxDocs=42740)
             0.085910685 = queryNorm
           3.4677513 = fieldWeight in 5187, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             6.9355025 = idf(docFreq=112, maxDocs=42740)
             0.5 = fieldNorm(doc=5187)
       3.2333007 = weight(author_txt:sparck in 5187) [ClassicSimilarity], result of:
         3.2333007 = score(doc=5187,freq=1.0), product of:
           0.80310774 = queryWeight, product of:
             1.1609789 = boost
             8.051972 = idf(docFreq=36, maxDocs=42740)
             0.085910685 = queryNorm
           4.025986 = fieldWeight in 5187, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             8.051972 = idf(docFreq=36, maxDocs=42740)
             0.5 = fieldNorm(doc=5187)
   

Similar documents (content)

1. Sparck Jones, K.: Some thoughts on classification for retrieval (1970) 2.28

   2.2825007 = sum of:
     2.2825007 = product of:
       2.377605 = sum of:
         0.06589229 = weight(abstract_txt:lacking in 328) [ClassicSimilarity], result of:
           0.06589229 = score(doc=328,freq=1.0), product of:
             0.13738461 = queryWeight, product of:
               7.6739063 = idf(docFreq=53, maxDocs=42740)
               0.017902825 = queryNorm
             0.47961915 = fieldWeight in 328, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               7.6739063 = idf(docFreq=53, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.07324445 = weight(abstract_txt:suggestion in 328) [ClassicSimilarity], result of:
           0.07324445 = score(doc=328,freq=1.0), product of:
             0.14742287 = queryWeight, product of:
               1.0358894 = boost
               7.9493184 = idf(docFreq=40, maxDocs=42740)
               0.017902825 = queryNorm
             0.4968324 = fieldWeight in 328, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               7.9493184 = idf(docFreq=40, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.07854215 = weight(abstract_txt:substantive in 328) [ClassicSimilarity], result of:
           0.07854215 = score(doc=328,freq=1.0), product of:
             0.15444845 = queryWeight, product of:
               1.0602853 = boost
               8.13653 = idf(docFreq=33, maxDocs=42740)
               0.017902825 = queryNorm
             0.5085331 = fieldWeight in 328, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.13653 = idf(docFreq=33, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.07940984 = weight(abstract_txt:proposition in 328) [ClassicSimilarity], result of:
           0.07940984 = score(doc=328,freq=1.0), product of:
             0.15558386 = queryWeight, product of:
               1.0641755 = boost
               8.166383 = idf(docFreq=32, maxDocs=42740)
               0.017902825 = queryNorm
             0.5103989 = fieldWeight in 328, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.166383 = idf(docFreq=32, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.08778736 = weight(abstract_txt:illustrative in 328) [ClassicSimilarity], result of:
           0.08778736 = score(doc=328,freq=1.0), product of:
             0.16634241 = queryWeight, product of:
               1.1003541 = boost
               8.444015 = idf(docFreq=24, maxDocs=42740)
               0.017902825 = queryNorm
             0.5277509 = fieldWeight in 328, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.444015 = idf(docFreq=24, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.033132665 = weight(abstract_txt:them in 328) [ClassicSimilarity], result of:
           0.033132665 = score(doc=328,freq=2.0), product of:
             0.086873226 = queryWeight, product of:
               1.1245763 = boost
               4.3149467 = idf(docFreq=1552, maxDocs=42740)
               0.017902825 = queryNorm
             0.381391 = fieldWeight in 328, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.3149467 = idf(docFreq=1552, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.02208471 = weight(abstract_txt:which in 328) [ClassicSimilarity], result of:
           0.02208471 = score(doc=328,freq=4.0), product of:
             0.060227737 = queryWeight, product of:
               1.1468058 = boost
               2.9334934 = idf(docFreq=6181, maxDocs=42740)
               0.017902825 = queryNorm
             0.36668667 = fieldWeight in 328, product of:
               2.0 = tf(freq=4.0), with freq of:
                 4.0 = termFreq=4.0
               2.9334934 = idf(docFreq=6181, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.03657499 = weight(abstract_txt:should in 328) [ClassicSimilarity], result of:
           0.03657499 = score(doc=328,freq=2.0), product of:
             0.09279071 = queryWeight, product of:
               1.1622465 = boost
               4.459485 = idf(docFreq=1343, maxDocs=42740)
               0.017902825 = queryNorm
             0.3941665 = fieldWeight in 328, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.459485 = idf(docFreq=1343, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.10980307 = weight(abstract_txt:goodness in 328) [ClassicSimilarity], result of:
           0.10980307 = score(doc=328,freq=1.0), product of:
             0.19310403 = queryWeight, product of:
               1.1855685 = boost
               9.097941 = idf(docFreq=12, maxDocs=42740)
               0.017902825 = queryNorm
             0.56862134 = fieldWeight in 328, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               9.097941 = idf(docFreq=12, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.01790857 = weight(abstract_txt:that in 328) [ClassicSimilarity], result of:
           0.01790857 = score(doc=328,freq=5.0), product of:
             0.053512134 = queryWeight, product of:
               1.2482084 = boost
               2.3946586 = idf(docFreq=10595, maxDocs=42740)
               0.017902825 = queryNorm
             0.33466372 = fieldWeight in 328, product of:
               2.236068 = tf(freq=5.0), with freq of:
                 5.0 = termFreq=5.0
               2.3946586 = idf(docFreq=10595, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.048627786 = weight(abstract_txt:since in 328) [ClassicSimilarity], result of:
           0.048627786 = score(doc=328,freq=2.0), product of:
             0.11219444 = queryWeight, product of:
               1.2780023 = boost
               4.903635 = idf(docFreq=861, maxDocs=42740)
               0.017902825 = queryNorm
             0.4334242 = fieldWeight in 328, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.903635 = idf(docFreq=861, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.14024451 = weight(abstract_txt:unordered in 328) [ClassicSimilarity], result of:
           0.14024451 = score(doc=328,freq=1.0), product of:
             0.22732067 = queryWeight, product of:
               1.2863241 = boost
               9.871131 = idf(docFreq=5, maxDocs=42740)
               0.017902825 = queryNorm
             0.6169457 = fieldWeight in 328, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               9.871131 = idf(docFreq=5, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.057983615 = weight(abstract_txt:automatic in 328) [ClassicSimilarity], result of:
           0.057983615 = score(doc=328,freq=2.0), product of:
             0.12615909 = queryWeight, product of:
               1.3552058 = boost
               5.199861 = idf(docFreq=640, maxDocs=42740)
               0.017902825 = queryNorm
             0.45960712 = fieldWeight in 328, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               5.199861 = idf(docFreq=640, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.06939826 = weight(abstract_txt:formal in 328) [ClassicSimilarity], result of:
           0.06939826 = score(doc=328,freq=2.0), product of:
             0.14221565 = queryWeight, product of:
               1.4388638 = boost
               5.520853 = idf(docFreq=464, maxDocs=42740)
               0.017902825 = queryNorm
             0.48797908 = fieldWeight in 328, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               5.520853 = idf(docFreq=464, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.084872425 = weight(abstract_txt:class in 328) [ClassicSimilarity], result of:
           0.084872425 = score(doc=328,freq=2.0), product of:
             0.16263953 = queryWeight, product of:
               1.538718 = boost
               5.903989 = idf(docFreq=316, maxDocs=42740)
               0.017902825 = queryNorm
             0.5218438 = fieldWeight in 328, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               5.903989 = idf(docFreq=316, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.09686111 = weight(abstract_txt:classifications in 328) [ClassicSimilarity], result of:
           0.09686111 = score(doc=328,freq=2.0), product of:
             0.17761569 = queryWeight, product of:
               1.6080022 = boost
               6.169829 = idf(docFreq=242, maxDocs=42740)
               0.017902825 = queryNorm
             0.54534096 = fieldWeight in 328, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               6.169829 = idf(docFreq=242, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.08969575 = weight(abstract_txt:precise in 328) [ClassicSimilarity], result of:
           0.08969575 = score(doc=328,freq=1.0), product of:
             0.21260473 = queryWeight, product of:
               1.7592697 = boost
               6.7502356 = idf(docFreq=135, maxDocs=42740)
               0.017902825 = queryNorm
             0.42188972 = fieldWeight in 328, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               6.7502356 = idf(docFreq=135, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.16713305 = weight(abstract_txt:sufficiently in 328) [ClassicSimilarity], result of:
           0.16713305 = score(doc=328,freq=2.0), product of:
             0.25551903 = queryWeight, product of:
               1.9286685 = boost
               7.400211 = idf(docFreq=70, maxDocs=42740)
               0.017902825 = queryNorm
             0.6540924 = fieldWeight in 328, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               7.400211 = idf(docFreq=70, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.07933065 = weight(abstract_txt:considered in 328) [ClassicSimilarity], result of:
           0.07933065 = score(doc=328,freq=2.0), product of:
             0.17798065 = queryWeight, product of:
               1.9714147 = boost
               5.042817 = idf(docFreq=749, maxDocs=42740)
               0.017902825 = queryNorm
             0.44572628 = fieldWeight in 328, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               5.042817 = idf(docFreq=749, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.22980319 = weight(abstract_txt:sorts in 328) [ClassicSimilarity], result of:
           0.22980319 = score(doc=328,freq=2.0), product of:
             0.3159505 = queryWeight, product of:
               2.1446455 = boost
               8.228904 = idf(docFreq=30, maxDocs=42740)
               0.017902825 = queryNorm
             0.7273392 = fieldWeight in 328, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               8.228904 = idf(docFreq=30, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.09227515 = weight(abstract_txt:purpose in 328) [ClassicSimilarity], result of:
           0.09227515 = score(doc=328,freq=3.0), product of:
             0.18927115 = queryWeight, product of:
               2.347487 = boost
               4.5035987 = idf(docFreq=1285, maxDocs=42740)
               0.017902825 = queryNorm
             0.48752886 = fieldWeight in 328, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               4.5035987 = idf(docFreq=1285, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.0727782 = weight(abstract_txt:retrieval in 328) [ClassicSimilarity], result of:
           0.0727782 = score(doc=328,freq=4.0), product of:
             0.16804011 = queryWeight, product of:
               2.7090254 = boost
               3.4648013 = idf(docFreq=3633, maxDocs=42740)
               0.017902825 = queryNorm
             0.43310016 = fieldWeight in 328, product of:
               2.0 = tf(freq=4.0), with freq of:
                 4.0 = termFreq=4.0
               3.4648013 = idf(docFreq=3633, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.19011709 = weight(abstract_txt:required in 328) [ClassicSimilarity], result of:
           0.19011709 = score(doc=328,freq=4.0), product of:
             0.2784384 = queryWeight, product of:
               2.8472495 = boost
               5.4623814 = idf(docFreq=492, maxDocs=42740)
               0.017902825 = queryNorm
             0.6827977 = fieldWeight in 328, product of:
               2.0 = tf(freq=4.0), with freq of:
                 4.0 = termFreq=4.0
               5.4623814 = idf(docFreq=492, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
         0.35410407 = weight(abstract_txt:classification in 328) [ClassicSimilarity], result of:
           0.35410407 = score(doc=328,freq=10.0), product of:
             0.44791546 = queryWeight, product of:
               6.2548895 = boost
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.017902825 = queryNorm
             0.79056007 = fieldWeight in 328, product of:
               3.1622777 = tf(freq=10.0), with freq of:
                 10.0 = termFreq=10.0
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.0625 = fieldNorm(doc=328)
       0.96 = coord(24/25)
   

2. Sparck Jones, K.: Revisiting classification for retrieval (2005) 0.27

   0.27466527 = sum of:
     0.27466527 = product of:
       0.9809474 = sum of:
         0.11781323 = weight(abstract_txt:substantive in 329) [ClassicSimilarity], result of:
           0.11781323 = score(doc=329,freq=1.0), product of:
             0.15444845 = queryWeight, product of:
               1.0602853 = boost
               8.13653 = idf(docFreq=33, maxDocs=42740)
               0.017902825 = queryNorm
             0.7627997 = fieldWeight in 329, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.13653 = idf(docFreq=33, maxDocs=42740)
               0.09375 = fieldNorm(doc=329)
         0.023424372 = weight(abstract_txt:which in 329) [ClassicSimilarity], result of:
           0.023424372 = score(doc=329,freq=2.0), product of:
             0.060227737 = queryWeight, product of:
               1.1468058 = boost
               2.9334934 = idf(docFreq=6181, maxDocs=42740)
               0.017902825 = queryNorm
             0.38892996 = fieldWeight in 329, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               2.9334934 = idf(docFreq=6181, maxDocs=42740)
               0.09375 = fieldNorm(doc=329)
         0.0120134335 = weight(abstract_txt:that in 329) [ClassicSimilarity], result of:
           0.0120134335 = score(doc=329,freq=1.0), product of:
             0.053512134 = queryWeight, product of:
               1.2482084 = boost
               2.3946586 = idf(docFreq=10595, maxDocs=42740)
               0.017902825 = queryNorm
             0.22449924 = fieldWeight in 329, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               2.3946586 = idf(docFreq=10595, maxDocs=42740)
               0.09375 = fieldNorm(doc=329)
         0.29500672 = weight(abstract_txt:1970 in 329) [ClassicSimilarity], result of:
           0.29500672 = score(doc=329,freq=2.0), product of:
             0.2848014 = queryWeight, product of:
               2.036184 = boost
               7.8127427 = idf(docFreq=46, maxDocs=42740)
               0.017902825 = queryNorm
             1.0358331 = fieldWeight in 329, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               7.8127427 = idf(docFreq=46, maxDocs=42740)
               0.09375 = fieldNorm(doc=329)
         0.07991262 = weight(abstract_txt:purpose in 329) [ClassicSimilarity], result of:
           0.07991262 = score(doc=329,freq=1.0), product of:
             0.18927115 = queryWeight, product of:
               2.347487 = boost
               4.5035987 = idf(docFreq=1285, maxDocs=42740)
               0.017902825 = queryNorm
             0.42221236 = fieldWeight in 329, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.5035987 = idf(docFreq=1285, maxDocs=42740)
               0.09375 = fieldNorm(doc=329)
         0.07719294 = weight(abstract_txt:retrieval in 329) [ClassicSimilarity], result of:
           0.07719294 = score(doc=329,freq=2.0), product of:
             0.16804011 = queryWeight, product of:
               2.7090254 = boost
               3.4648013 = idf(docFreq=3633, maxDocs=42740)
               0.017902825 = queryNorm
             0.4593721 = fieldWeight in 329, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.4648013 = idf(docFreq=3633, maxDocs=42740)
               0.09375 = fieldNorm(doc=329)
         0.3755841 = weight(abstract_txt:classification in 329) [ClassicSimilarity], result of:
           0.3755841 = score(doc=329,freq=5.0), product of:
             0.44791546 = queryWeight, product of:
               6.2548895 = boost
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.017902825 = queryNorm
             0.8385156 = fieldWeight in 329, product of:
               2.236068 = tf(freq=5.0), with freq of:
                 5.0 = termFreq=5.0
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.09375 = fieldNorm(doc=329)
       0.28 = coord(7/25)
   

3. Bahls, D.; Scherp, G.; Tochtermann, K.; Hasselbring, W.: Towards a recommender system for statistical research data (2012) 0.18

   0.17501308 = sum of:
     0.17501308 = product of:
       0.5469159 = sum of:
         0.06589229 = weight(abstract_txt:lacking in 2475) [ClassicSimilarity], result of:
           0.06589229 = score(doc=2475,freq=1.0), product of:
             0.13738461 = queryWeight, product of:
               7.6739063 = idf(docFreq=53, maxDocs=42740)
               0.017902825 = queryNorm
             0.47961915 = fieldWeight in 2475, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               7.6739063 = idf(docFreq=53, maxDocs=42740)
               0.0625 = fieldNorm(doc=2475)
         0.015616247 = weight(abstract_txt:which in 2475) [ClassicSimilarity], result of:
           0.015616247 = score(doc=2475,freq=2.0), product of:
             0.060227737 = queryWeight, product of:
               1.1468058 = boost
               2.9334934 = idf(docFreq=6181, maxDocs=42740)
               0.017902825 = queryNorm
             0.25928664 = fieldWeight in 2475, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               2.9334934 = idf(docFreq=6181, maxDocs=42740)
               0.0625 = fieldNorm(doc=2475)
         0.008008956 = weight(abstract_txt:that in 2475) [ClassicSimilarity], result of:
           0.008008956 = score(doc=2475,freq=1.0), product of:
             0.053512134 = queryWeight, product of:
               1.2482084 = boost
               2.3946586 = idf(docFreq=10595, maxDocs=42740)
               0.017902825 = queryNorm
             0.14966616 = fieldWeight in 2475, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               2.3946586 = idf(docFreq=10595, maxDocs=42740)
               0.0625 = fieldNorm(doc=2475)
         0.034385037 = weight(abstract_txt:since in 2475) [ClassicSimilarity], result of:
           0.034385037 = score(doc=2475,freq=1.0), product of:
             0.11219444 = queryWeight, product of:
               1.2780023 = boost
               4.903635 = idf(docFreq=861, maxDocs=42740)
               0.017902825 = queryNorm
             0.3064772 = fieldWeight in 2475, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.903635 = idf(docFreq=861, maxDocs=42740)
               0.0625 = fieldNorm(doc=2475)
         0.08969575 = weight(abstract_txt:precise in 2475) [ClassicSimilarity], result of:
           0.08969575 = score(doc=2475,freq=1.0), product of:
             0.21260473 = queryWeight, product of:
               1.7592697 = boost
               6.7502356 = idf(docFreq=135, maxDocs=42740)
               0.017902825 = queryNorm
             0.42188972 = fieldWeight in 2475, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               6.7502356 = idf(docFreq=135, maxDocs=42740)
               0.0625 = fieldNorm(doc=2475)
         0.1624954 = weight(abstract_txt:sorts in 2475) [ClassicSimilarity], result of:
           0.1624954 = score(doc=2475,freq=1.0), product of:
             0.3159505 = queryWeight, product of:
               2.1446455 = boost
               8.228904 = idf(docFreq=30, maxDocs=42740)
               0.017902825 = queryNorm
             0.5143065 = fieldWeight in 2475, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.228904 = idf(docFreq=30, maxDocs=42740)
               0.0625 = fieldNorm(doc=2475)
         0.0363891 = weight(abstract_txt:retrieval in 2475) [ClassicSimilarity], result of:
           0.0363891 = score(doc=2475,freq=1.0), product of:
             0.16804011 = queryWeight, product of:
               2.7090254 = boost
               3.4648013 = idf(docFreq=3633, maxDocs=42740)
               0.017902825 = queryNorm
             0.21655008 = fieldWeight in 2475, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.4648013 = idf(docFreq=3633, maxDocs=42740)
               0.0625 = fieldNorm(doc=2475)
         0.13443308 = weight(abstract_txt:required in 2475) [ClassicSimilarity], result of:
           0.13443308 = score(doc=2475,freq=2.0), product of:
             0.2784384 = queryWeight, product of:
               2.8472495 = boost
               5.4623814 = idf(docFreq=492, maxDocs=42740)
               0.017902825 = queryNorm
             0.48281085 = fieldWeight in 2475, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               5.4623814 = idf(docFreq=492, maxDocs=42740)
               0.0625 = fieldNorm(doc=2475)
       0.32 = coord(8/25)
   

4. Golub, K.; Lykke, M.: Automated classification of web pages in hierarchical browsing (2009) 0.16

   0.15940441 = sum of:
     0.15940441 = product of:
       0.5693015 = sum of:
         0.013664217 = weight(abstract_txt:which in 615) [ClassicSimilarity], result of:
           0.013664217 = score(doc=615,freq=2.0), product of:
             0.060227737 = queryWeight, product of:
               1.1468058 = boost
               2.9334934 = idf(docFreq=6181, maxDocs=42740)
               0.017902825 = queryNorm
             0.22687581 = fieldWeight in 615, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               2.9334934 = idf(docFreq=6181, maxDocs=42740)
               0.0546875 = fieldNorm(doc=615)
         0.02262962 = weight(abstract_txt:should in 615) [ClassicSimilarity], result of:
           0.02262962 = score(doc=615,freq=1.0), product of:
             0.09279071 = queryWeight, product of:
               1.1622465 = boost
               4.459485 = idf(docFreq=1343, maxDocs=42740)
               0.017902825 = queryNorm
             0.2438781 = fieldWeight in 615, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.459485 = idf(docFreq=1343, maxDocs=42740)
               0.0546875 = fieldNorm(doc=615)
         0.007007836 = weight(abstract_txt:that in 615) [ClassicSimilarity], result of:
           0.007007836 = score(doc=615,freq=1.0), product of:
             0.053512134 = queryWeight, product of:
               1.2482084 = boost
               2.3946586 = idf(docFreq=10595, maxDocs=42740)
               0.017902825 = queryNorm
             0.13095789 = fieldWeight in 615, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               2.3946586 = idf(docFreq=10595, maxDocs=42740)
               0.0546875 = fieldNorm(doc=615)
         0.030086908 = weight(abstract_txt:since in 615) [ClassicSimilarity], result of:
           0.030086908 = score(doc=615,freq=1.0), product of:
             0.11219444 = queryWeight, product of:
               1.2780023 = boost
               4.903635 = idf(docFreq=861, maxDocs=42740)
               0.017902825 = queryNorm
             0.26816756 = fieldWeight in 615, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.903635 = idf(docFreq=861, maxDocs=42740)
               0.0546875 = fieldNorm(doc=615)
         0.10502428 = weight(abstract_txt:class in 615) [ClassicSimilarity], result of:
           0.10502428 = score(doc=615,freq=4.0), product of:
             0.16263953 = queryWeight, product of:
               1.538718 = boost
               5.903989 = idf(docFreq=316, maxDocs=42740)
               0.017902825 = queryNorm
             0.6457488 = fieldWeight in 615, product of:
               2.0 = tf(freq=4.0), with freq of:
                 4.0 = termFreq=4.0
               5.903989 = idf(docFreq=316, maxDocs=42740)
               0.0546875 = fieldNorm(doc=615)
         0.06592455 = weight(abstract_txt:purpose in 615) [ClassicSimilarity], result of:
           0.06592455 = score(doc=615,freq=2.0), product of:
             0.18927115 = queryWeight, product of:
               2.347487 = boost
               4.5035987 = idf(docFreq=1285, maxDocs=42740)
               0.017902825 = queryNorm
             0.34830743 = fieldWeight in 615, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.5035987 = idf(docFreq=1285, maxDocs=42740)
               0.0546875 = fieldNorm(doc=615)
         0.32496408 = weight(abstract_txt:classification in 615) [ClassicSimilarity], result of:
           0.32496408 = score(doc=615,freq=11.0), product of:
             0.44791546 = queryWeight, product of:
               6.2548895 = boost
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.017902825 = queryNorm
             0.72550315 = fieldWeight in 615, product of:
               3.3166249 = tf(freq=11.0), with freq of:
                 11.0 = termFreq=11.0
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.0546875 = fieldNorm(doc=615)
       0.28 = coord(7/25)
   

5. Liu, S.; Svenonius, E.: DORS: DDC online retrieval system (1991) 0.16

   0.1573284 = sum of:
     0.1573284 = product of:
       0.655535 = sum of:
         0.040999584 = weight(abstract_txt:them in 1155) [ClassicSimilarity], result of:
           0.040999584 = score(doc=1155,freq=1.0), product of:
             0.086873226 = queryWeight, product of:
               1.1245763 = boost
               4.3149467 = idf(docFreq=1552, maxDocs=42740)
               0.017902825 = queryNorm
             0.47194728 = fieldWeight in 1155, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.3149467 = idf(docFreq=1552, maxDocs=42740)
               0.109375 = fieldNorm(doc=1155)
         0.014015672 = weight(abstract_txt:that in 1155) [ClassicSimilarity], result of:
           0.014015672 = score(doc=1155,freq=1.0), product of:
             0.053512134 = queryWeight, product of:
               1.2482084 = boost
               2.3946586 = idf(docFreq=10595, maxDocs=42740)
               0.017902825 = queryNorm
             0.26191577 = fieldWeight in 1155, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               2.3946586 = idf(docFreq=10595, maxDocs=42740)
               0.109375 = fieldNorm(doc=1155)
         0.11985951 = weight(abstract_txt:classifications in 1155) [ClassicSimilarity], result of:
           0.11985951 = score(doc=1155,freq=1.0), product of:
             0.17761569 = queryWeight, product of:
               1.6080022 = boost
               6.169829 = idf(docFreq=242, maxDocs=42740)
               0.017902825 = queryNorm
             0.674825 = fieldWeight in 1155, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               6.169829 = idf(docFreq=242, maxDocs=42740)
               0.109375 = fieldNorm(doc=1155)
         0.093231395 = weight(abstract_txt:purpose in 1155) [ClassicSimilarity], result of:
           0.093231395 = score(doc=1155,freq=1.0), product of:
             0.18927115 = queryWeight, product of:
               2.347487 = boost
               4.5035987 = idf(docFreq=1285, maxDocs=42740)
               0.017902825 = queryNorm
             0.4925811 = fieldWeight in 1155, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.5035987 = idf(docFreq=1285, maxDocs=42740)
               0.109375 = fieldNorm(doc=1155)
         0.11029859 = weight(abstract_txt:retrieval in 1155) [ClassicSimilarity], result of:
           0.11029859 = score(doc=1155,freq=3.0), product of:
             0.16804011 = queryWeight, product of:
               2.7090254 = boost
               3.4648013 = idf(docFreq=3633, maxDocs=42740)
               0.017902825 = queryNorm
             0.6563825 = fieldWeight in 1155, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               3.4648013 = idf(docFreq=3633, maxDocs=42740)
               0.109375 = fieldNorm(doc=1155)
         0.27713028 = weight(abstract_txt:classification in 1155) [ClassicSimilarity], result of:
           0.27713028 = score(doc=1155,freq=2.0), product of:
             0.44791546 = queryWeight, product of:
               6.2548895 = boost
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.017902825 = queryNorm
             0.6187111 = fieldWeight in 1155, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.109375 = fieldNorm(doc=1155)
       0.24 = coord(6/25)