Document (#38231)

Author

Boyack, K.W.
Klavans, R.

Title

Creation of a highly detailed, dynamic, global model and map of science

Source

Journal of the Association for Information Science and Technology. 65(2014) no.4, S.670-685

Year

2014

Abstract

The majority of the effort in metrics research has addressed research evaluation. Far less research has addressed the unique problems of research planning. Models and maps of science that can address the detailed problems associated with research planning are needed. This article reports on the creation of an article-level model and map of science covering 16 years and nearly 20 million articles using cocitation-based techniques. The map is then used to define discipline-like structures consisting of natural groupings of articles and clusters of articles. This combination of detail and high-level structure can be used to address planning-related problems such as identification of emerging topics and the identification of which areas of science and technology are innovative and which are simply persisting. In addition to presenting the model and map, several process improvements that result in greater accuracy structures are detailed, including a bibliographic coupling approach for assigning current papers to cocitation clusters and a sequential hybrid approach to producing visual maps from models.

Theme

Informetrie

Similar documents (author)

1. Klavans, R.; Boyack, K.W.: Identifying a better measure of relatedness for mapping science (2006) 6.49

   6.4887934 = sum of:
     6.4887934 = sum of:
       3.2019496 = weight(author_txt:boyack in 252) [ClassicSimilarity], result of:
         3.2019496 = score(doc=252,freq=1.0), product of:
           0.7009124 = queryWeight, product of:
             9.1365185 = idf(docFreq=12, maxDocs=44421)
             0.076715484 = queryNorm
           4.5682592 = fieldWeight in 252, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             9.1365185 = idf(docFreq=12, maxDocs=44421)
             0.5 = fieldNorm(doc=252)
       3.286844 = weight(author_txt:klavans in 252) [ClassicSimilarity], result of:
         3.286844 = score(doc=252,freq=1.0), product of:
           0.71324736 = queryWeight, product of:
             1.0087608 = boost
             9.216561 = idf(docFreq=11, maxDocs=44421)
             0.076715484 = queryNorm
           4.6082807 = fieldWeight in 252, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             9.216561 = idf(docFreq=11, maxDocs=44421)
             0.5 = fieldNorm(doc=252)
   

2. Klavans, R.; Boyack, K.W.: Toward a consensus map of science (2009) 6.49

   6.4887934 = sum of:
     6.4887934 = sum of:
       3.2019496 = weight(author_txt:boyack in 3736) [ClassicSimilarity], result of:
         3.2019496 = score(doc=3736,freq=1.0), product of:
           0.7009124 = queryWeight, product of:
             9.1365185 = idf(docFreq=12, maxDocs=44421)
             0.076715484 = queryNorm
           4.5682592 = fieldWeight in 3736, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             9.1365185 = idf(docFreq=12, maxDocs=44421)
             0.5 = fieldNorm(doc=3736)
       3.286844 = weight(author_txt:klavans in 3736) [ClassicSimilarity], result of:
         3.286844 = score(doc=3736,freq=1.0), product of:
           0.71324736 = queryWeight, product of:
             1.0087608 = boost
             9.216561 = idf(docFreq=11, maxDocs=44421)
             0.076715484 = queryNorm
           4.6082807 = fieldWeight in 3736, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             9.216561 = idf(docFreq=11, maxDocs=44421)
             0.5 = fieldNorm(doc=3736)
   

3. Boyack, K.W.; Klavans, R.: Co-citation analysis, bibliographic coupling, and direct citation : which citation approach represents the research front most accurately? (2010) 6.49

   6.4887934 = sum of:
     6.4887934 = sum of:
       3.2019496 = weight(author_txt:boyack in 111) [ClassicSimilarity], result of:
         3.2019496 = score(doc=111,freq=1.0), product of:
           0.7009124 = queryWeight, product of:
             9.1365185 = idf(docFreq=12, maxDocs=44421)
             0.076715484 = queryNorm
           4.5682592 = fieldWeight in 111, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             9.1365185 = idf(docFreq=12, maxDocs=44421)
             0.5 = fieldNorm(doc=111)
       3.286844 = weight(author_txt:klavans in 111) [ClassicSimilarity], result of:
         3.286844 = score(doc=111,freq=1.0), product of:
           0.71324736 = queryWeight, product of:
             1.0087608 = boost
             9.216561 = idf(docFreq=11, maxDocs=44421)
             0.076715484 = queryNorm
           4.6082807 = fieldWeight in 111, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             9.216561 = idf(docFreq=11, maxDocs=44421)
             0.5 = fieldNorm(doc=111)
   

4. Klavans, R.; Boyack, K.W.: Using global mapping to create more accurate document-level maps of research fields (2011) 6.49

   6.4887934 = sum of:
     6.4887934 = sum of:
       3.2019496 = weight(author_txt:boyack in 956) [ClassicSimilarity], result of:
         3.2019496 = score(doc=956,freq=1.0), product of:
           0.7009124 = queryWeight, product of:
             9.1365185 = idf(docFreq=12, maxDocs=44421)
             0.076715484 = queryNorm
           4.5682592 = fieldWeight in 956, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             9.1365185 = idf(docFreq=12, maxDocs=44421)
             0.5 = fieldNorm(doc=956)
       3.286844 = weight(author_txt:klavans in 956) [ClassicSimilarity], result of:
         3.286844 = score(doc=956,freq=1.0), product of:
           0.71324736 = queryWeight, product of:
             1.0087608 = boost
             9.216561 = idf(docFreq=11, maxDocs=44421)
             0.076715484 = queryNorm
           4.6082807 = fieldWeight in 956, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             9.216561 = idf(docFreq=11, maxDocs=44421)
             0.5 = fieldNorm(doc=956)
   

5. Klavans, K.; Boyack, K.W.: Which type of citation analysis generates the most accurate taxonomy of scientific and technical knowledge? (2017) 6.49

   6.4887934 = sum of:
     6.4887934 = sum of:
       3.2019496 = weight(author_txt:boyack in 4535) [ClassicSimilarity], result of:
         3.2019496 = score(doc=4535,freq=1.0), product of:
           0.7009124 = queryWeight, product of:
             9.1365185 = idf(docFreq=12, maxDocs=44421)
             0.076715484 = queryNorm
           4.5682592 = fieldWeight in 4535, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             9.1365185 = idf(docFreq=12, maxDocs=44421)
             0.5 = fieldNorm(doc=4535)
       3.286844 = weight(author_txt:klavans in 4535) [ClassicSimilarity], result of:
         3.286844 = score(doc=4535,freq=1.0), product of:
           0.71324736 = queryWeight, product of:
             1.0087608 = boost
             9.216561 = idf(docFreq=11, maxDocs=44421)
             0.076715484 = queryNorm
           4.6082807 = fieldWeight in 4535, product of:
             1.0 = tf(freq=1.0), with freq of:
               1.0 = termFreq=1.0
             9.216561 = idf(docFreq=11, maxDocs=44421)
             0.5 = fieldNorm(doc=4535)
   

Similar documents (content)

1. Colavizza, G.; Boyack, K.W.; Eck, N.J. van; Waltman, L.: ¬The closer the better : similarity of publication pairs at different cocitation levels (2018) 0.22

   0.22066201 = sum of:
     0.22066201 = product of:
       0.7880786 = sum of:
         0.035854224 = weight(abstract_txt:article in 214) [ClassicSimilarity], result of:
           0.035854224 = score(doc=214,freq=2.0), product of:
             0.0854134 = queryWeight, product of:
               1.1131555 = boost
               3.79935 = idf(docFreq=2702, maxDocs=44421)
               0.020195791 = queryNorm
             0.41977283 = fieldWeight in 214, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.79935 = idf(docFreq=2702, maxDocs=44421)
               0.078125 = fieldNorm(doc=214)
         0.059378296 = weight(abstract_txt:level in 214) [ClassicSimilarity], result of:
           0.059378296 = score(doc=214,freq=2.0), product of:
             0.11955955 = queryWeight, product of:
               1.3169975 = boost
               4.4950905 = idf(docFreq=1347, maxDocs=44421)
               0.020195791 = queryNorm
             0.49664202 = fieldWeight in 214, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.4950905 = idf(docFreq=1347, maxDocs=44421)
               0.078125 = fieldNorm(doc=214)
         0.09461907 = weight(abstract_txt:maps in 214) [ClassicSimilarity], result of:
           0.09461907 = score(doc=214,freq=1.0), product of:
             0.20550777 = queryWeight, product of:
               1.7266605 = boost
               5.8933253 = idf(docFreq=332, maxDocs=44421)
               0.020195791 = queryNorm
             0.46041605 = fieldWeight in 214, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.8933253 = idf(docFreq=332, maxDocs=44421)
               0.078125 = fieldNorm(doc=214)
         0.07572171 = weight(abstract_txt:articles in 214) [ClassicSimilarity], result of:
           0.07572171 = score(doc=214,freq=1.0), product of:
             0.20277752 = queryWeight, product of:
               2.100624 = boost
               4.7798095 = idf(docFreq=1013, maxDocs=44421)
               0.020195791 = queryNorm
             0.37342262 = fieldWeight in 214, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.7798095 = idf(docFreq=1013, maxDocs=44421)
               0.078125 = fieldNorm(doc=214)
         0.41816917 = weight(abstract_txt:cocitation in 214) [ClassicSimilarity], result of:
           0.41816917 = score(doc=214,freq=4.0), product of:
             0.34865063 = queryWeight, product of:
               2.2489927 = boost
               7.676116 = idf(docFreq=55, maxDocs=44421)
               0.020195791 = queryNorm
             1.1993932 = fieldWeight in 214, product of:
               2.0 = tf(freq=4.0), with freq of:
                 4.0 = termFreq=4.0
               7.676116 = idf(docFreq=55, maxDocs=44421)
               0.078125 = fieldNorm(doc=214)
         0.052784644 = weight(abstract_txt:science in 214) [ClassicSimilarity], result of:
           0.052784644 = score(doc=214,freq=1.0), product of:
             0.17546514 = queryWeight, product of:
               2.256333 = boost
               3.850585 = idf(docFreq=2567, maxDocs=44421)
               0.020195791 = queryNorm
             0.30082697 = fieldWeight in 214, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.850585 = idf(docFreq=2567, maxDocs=44421)
               0.078125 = fieldNorm(doc=214)
         0.051551502 = weight(abstract_txt:research in 214) [ClassicSimilarity], result of:
           0.051551502 = score(doc=214,freq=2.0), product of:
             0.1476749 = queryWeight, product of:
               2.3142815 = boost
               3.159582 = idf(docFreq=5124, maxDocs=44421)
               0.020195791 = queryNorm
             0.34908777 = fieldWeight in 214, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.159582 = idf(docFreq=5124, maxDocs=44421)
               0.078125 = fieldNorm(doc=214)
       0.28 = coord(7/25)
   

2. Coleman, A.S.; Bracke, P.: Controlled vocabularies as a sphere of influence (2006) 0.16

   0.16254468 = sum of:
     0.16254468 = product of:
       0.50795215 = sum of:
         0.020282213 = weight(abstract_txt:article in 2491) [ClassicSimilarity], result of:
           0.020282213 = score(doc=2491,freq=1.0), product of:
             0.0854134 = queryWeight, product of:
               1.1131555 = boost
               3.79935 = idf(docFreq=2702, maxDocs=44421)
               0.020195791 = queryNorm
             0.23745938 = fieldWeight in 2491, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.79935 = idf(docFreq=2702, maxDocs=44421)
               0.0625 = fieldNorm(doc=2491)
         0.089492254 = weight(abstract_txt:coupling in 2491) [ClassicSimilarity], result of:
           0.089492254 = score(doc=2491,freq=1.0), product of:
             0.18237393 = queryWeight, product of:
               1.1501625 = boost
               7.85132 = idf(docFreq=46, maxDocs=44421)
               0.020195791 = queryNorm
             0.4907075 = fieldWeight in 2491, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               7.85132 = idf(docFreq=46, maxDocs=44421)
               0.0625 = fieldNorm(doc=2491)
         0.05031592 = weight(abstract_txt:creation in 2491) [ClassicSimilarity], result of:
           0.05031592 = score(doc=2491,freq=1.0), product of:
             0.15652585 = queryWeight, product of:
               1.506905 = boost
               5.14327 = idf(docFreq=704, maxDocs=44421)
               0.020195791 = queryNorm
             0.32145438 = fieldWeight in 2491, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.14327 = idf(docFreq=704, maxDocs=44421)
               0.0625 = fieldNorm(doc=2491)
         0.05910118 = weight(abstract_txt:address in 2491) [ClassicSimilarity], result of:
           0.05910118 = score(doc=2491,freq=1.0), product of:
             0.17425285 = queryWeight, product of:
               1.5899475 = boost
               5.4267054 = idf(docFreq=530, maxDocs=44421)
               0.020195791 = queryNorm
             0.33916909 = fieldWeight in 2491, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.4267054 = idf(docFreq=530, maxDocs=44421)
               0.0625 = fieldNorm(doc=2491)
         0.10248659 = weight(abstract_txt:clusters in 2491) [ClassicSimilarity], result of:
           0.10248659 = score(doc=2491,freq=1.0), product of:
             0.25151303 = queryWeight, product of:
               1.9101746 = boost
               6.519684 = idf(docFreq=177, maxDocs=44421)
               0.020195791 = queryNorm
             0.40748024 = fieldWeight in 2491, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               6.519684 = idf(docFreq=177, maxDocs=44421)
               0.0625 = fieldNorm(doc=2491)
         0.06057737 = weight(abstract_txt:articles in 2491) [ClassicSimilarity], result of:
           0.06057737 = score(doc=2491,freq=1.0), product of:
             0.20277752 = queryWeight, product of:
               2.100624 = boost
               4.7798095 = idf(docFreq=1013, maxDocs=44421)
               0.020195791 = queryNorm
             0.2987381 = fieldWeight in 2491, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.7798095 = idf(docFreq=1013, maxDocs=44421)
               0.0625 = fieldNorm(doc=2491)
         0.08445543 = weight(abstract_txt:science in 2491) [ClassicSimilarity], result of:
           0.08445543 = score(doc=2491,freq=4.0), product of:
             0.17546514 = queryWeight, product of:
               2.256333 = boost
               3.850585 = idf(docFreq=2567, maxDocs=44421)
               0.020195791 = queryNorm
             0.48132312 = fieldWeight in 2491, product of:
               2.0 = tf(freq=4.0), with freq of:
                 4.0 = termFreq=4.0
               3.850585 = idf(docFreq=2567, maxDocs=44421)
               0.0625 = fieldNorm(doc=2491)
         0.041241206 = weight(abstract_txt:research in 2491) [ClassicSimilarity], result of:
           0.041241206 = score(doc=2491,freq=2.0), product of:
             0.1476749 = queryWeight, product of:
               2.3142815 = boost
               3.159582 = idf(docFreq=5124, maxDocs=44421)
               0.020195791 = queryNorm
             0.27927023 = fieldWeight in 2491, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.159582 = idf(docFreq=5124, maxDocs=44421)
               0.0625 = fieldNorm(doc=2491)
       0.32 = coord(8/25)
   

3. Raan, A.F.J. van; Noyons, E.C.M.: Discovery of patterns of scientific and technological development and knowledge transfer (2002) 0.14

   0.14072417 = sum of:
     0.14072417 = product of:
       0.439763 = sum of:
         0.019364249 = weight(abstract_txt:approach in 4603) [ClassicSimilarity], result of:
           0.019364249 = score(doc=4603,freq=1.0), product of:
             0.08281638 = queryWeight, product of:
               1.0961019 = boost
               3.741144 = idf(docFreq=2864, maxDocs=44421)
               0.020195791 = queryNorm
             0.2338215 = fieldWeight in 4603, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.741144 = idf(docFreq=2864, maxDocs=44421)
               0.0625 = fieldNorm(doc=4603)
         0.05031592 = weight(abstract_txt:creation in 4603) [ClassicSimilarity], result of:
           0.05031592 = score(doc=4603,freq=1.0), product of:
             0.15652585 = queryWeight, product of:
               1.506905 = boost
               5.14327 = idf(docFreq=704, maxDocs=44421)
               0.020195791 = queryNorm
             0.32145438 = fieldWeight in 4603, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.14327 = idf(docFreq=704, maxDocs=44421)
               0.0625 = fieldNorm(doc=4603)
         0.07336316 = weight(abstract_txt:identification in 4603) [ClassicSimilarity], result of:
           0.07336316 = score(doc=4603,freq=1.0), product of:
             0.2012648 = queryWeight, product of:
               1.708743 = boost
               5.8321705 = idf(docFreq=353, maxDocs=44421)
               0.020195791 = queryNorm
             0.36451066 = fieldWeight in 4603, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.8321705 = idf(docFreq=353, maxDocs=44421)
               0.0625 = fieldNorm(doc=4603)
         0.07569526 = weight(abstract_txt:maps in 4603) [ClassicSimilarity], result of:
           0.07569526 = score(doc=4603,freq=1.0), product of:
             0.20550777 = queryWeight, product of:
               1.7266605 = boost
               5.8933253 = idf(docFreq=332, maxDocs=44421)
               0.020195791 = queryNorm
             0.36833283 = fieldWeight in 4603, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.8933253 = idf(docFreq=332, maxDocs=44421)
               0.0625 = fieldNorm(doc=4603)
         0.044130683 = weight(abstract_txt:problems in 4603) [ClassicSimilarity], result of:
           0.044130683 = score(doc=4603,freq=1.0), product of:
             0.16417485 = queryWeight, product of:
               1.8901305 = boost
               4.300847 = idf(docFreq=1636, maxDocs=44421)
               0.020195791 = queryNorm
             0.26880294 = fieldWeight in 4603, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.300847 = idf(docFreq=1636, maxDocs=44421)
               0.0625 = fieldNorm(doc=4603)
         0.042227715 = weight(abstract_txt:science in 4603) [ClassicSimilarity], result of:
           0.042227715 = score(doc=4603,freq=1.0), product of:
             0.17546514 = queryWeight, product of:
               2.256333 = boost
               3.850585 = idf(docFreq=2567, maxDocs=44421)
               0.020195791 = queryNorm
             0.24066156 = fieldWeight in 4603, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.850585 = idf(docFreq=2567, maxDocs=44421)
               0.0625 = fieldNorm(doc=4603)
         0.029161934 = weight(abstract_txt:research in 4603) [ClassicSimilarity], result of:
           0.029161934 = score(doc=4603,freq=1.0), product of:
             0.1476749 = queryWeight, product of:
               2.3142815 = boost
               3.159582 = idf(docFreq=5124, maxDocs=44421)
               0.020195791 = queryNorm
             0.19747387 = fieldWeight in 4603, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.159582 = idf(docFreq=5124, maxDocs=44421)
               0.0625 = fieldNorm(doc=4603)
         0.10550406 = weight(abstract_txt:detailed in 4603) [ClassicSimilarity], result of:
           0.10550406 = score(doc=4603,freq=1.0), product of:
             0.2935344 = queryWeight, product of:
               2.527365 = boost
               5.750825 = idf(docFreq=383, maxDocs=44421)
               0.020195791 = queryNorm
             0.35942656 = fieldWeight in 4603, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.750825 = idf(docFreq=383, maxDocs=44421)
               0.0625 = fieldNorm(doc=4603)
       0.32 = coord(8/25)
   

4. Small, H.G.: Structural dynamics of scientific literature (2015) 0.13

   0.13238086 = sum of:
     0.13238086 = product of:
       0.6619043 = sum of:
         0.06202481 = weight(abstract_txt:structures in 3356) [ClassicSimilarity], result of:
           0.06202481 = score(doc=3356,freq=1.0), product of:
             0.15507892 = queryWeight, product of:
               1.4999238 = boost
               5.1194425 = idf(docFreq=721, maxDocs=44421)
               0.020195791 = queryNorm
             0.39995643 = fieldWeight in 3356, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.1194425 = idf(docFreq=721, maxDocs=44421)
               0.078125 = fieldNorm(doc=3356)
         0.28645876 = weight(abstract_txt:clusters in 3356) [ClassicSimilarity], result of:
           0.28645876 = score(doc=3356,freq=5.0), product of:
             0.25151303 = queryWeight, product of:
               1.9101746 = boost
               6.519684 = idf(docFreq=177, maxDocs=44421)
               0.020195791 = queryNorm
             1.138942 = fieldWeight in 3356, product of:
               2.236068 = tf(freq=5.0), with freq of:
                 5.0 = termFreq=5.0
               6.519684 = idf(docFreq=177, maxDocs=44421)
               0.078125 = fieldNorm(doc=3356)
         0.20908459 = weight(abstract_txt:cocitation in 3356) [ClassicSimilarity], result of:
           0.20908459 = score(doc=3356,freq=1.0), product of:
             0.34865063 = queryWeight, product of:
               2.2489927 = boost
               7.676116 = idf(docFreq=55, maxDocs=44421)
               0.020195791 = queryNorm
             0.5996966 = fieldWeight in 3356, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               7.676116 = idf(docFreq=55, maxDocs=44421)
               0.078125 = fieldNorm(doc=3356)
         0.052784644 = weight(abstract_txt:science in 3356) [ClassicSimilarity], result of:
           0.052784644 = score(doc=3356,freq=1.0), product of:
             0.17546514 = queryWeight, product of:
               2.256333 = boost
               3.850585 = idf(docFreq=2567, maxDocs=44421)
               0.020195791 = queryNorm
             0.30082697 = fieldWeight in 3356, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.850585 = idf(docFreq=2567, maxDocs=44421)
               0.078125 = fieldNorm(doc=3356)
         0.051551502 = weight(abstract_txt:research in 3356) [ClassicSimilarity], result of:
           0.051551502 = score(doc=3356,freq=2.0), product of:
             0.1476749 = queryWeight, product of:
               2.3142815 = boost
               3.159582 = idf(docFreq=5124, maxDocs=44421)
               0.020195791 = queryNorm
             0.34908777 = fieldWeight in 3356, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.159582 = idf(docFreq=5124, maxDocs=44421)
               0.078125 = fieldNorm(doc=3356)
       0.2 = coord(5/25)
   

5. Pors, N.O.: Information retrieval, experimental models and statistical analysis (2000) 0.13

   0.13149947 = sum of:
     0.13149947 = product of:
       0.54791445 = sum of:
         0.050384156 = weight(abstract_txt:level in 5548) [ClassicSimilarity], result of:
           0.050384156 = score(doc=5548,freq=1.0), product of:
             0.11955955 = queryWeight, product of:
               1.3169975 = boost
               4.4950905 = idf(docFreq=1347, maxDocs=44421)
               0.020195791 = queryNorm
             0.42141473 = fieldWeight in 5548, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.4950905 = idf(docFreq=1347, maxDocs=44421)
               0.09375 = fieldNorm(doc=5548)
         0.052568983 = weight(abstract_txt:model in 5548) [ClassicSimilarity], result of:
           0.052568983 = score(doc=5548,freq=1.0), product of:
             0.14078999 = queryWeight, product of:
               1.7503477 = boost
               3.9827821 = idf(docFreq=2249, maxDocs=44421)
               0.020195791 = queryNorm
             0.37338582 = fieldWeight in 5548, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.9827821 = idf(docFreq=2249, maxDocs=44421)
               0.09375 = fieldNorm(doc=5548)
         0.093615316 = weight(abstract_txt:problems in 5548) [ClassicSimilarity], result of:
           0.093615316 = score(doc=5548,freq=2.0), product of:
             0.16417485 = queryWeight, product of:
               1.8901305 = boost
               4.300847 = idf(docFreq=1636, maxDocs=44421)
               0.020195791 = queryNorm
             0.57021713 = fieldWeight in 5548, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.300847 = idf(docFreq=1636, maxDocs=44421)
               0.09375 = fieldNorm(doc=5548)
         0.06334157 = weight(abstract_txt:science in 5548) [ClassicSimilarity], result of:
           0.06334157 = score(doc=5548,freq=1.0), product of:
             0.17546514 = queryWeight, product of:
               2.256333 = boost
               3.850585 = idf(docFreq=2567, maxDocs=44421)
               0.020195791 = queryNorm
             0.36099234 = fieldWeight in 5548, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.850585 = idf(docFreq=2567, maxDocs=44421)
               0.09375 = fieldNorm(doc=5548)
         0.0978121 = weight(abstract_txt:research in 5548) [ClassicSimilarity], result of:
           0.0978121 = score(doc=5548,freq=5.0), product of:
             0.1476749 = queryWeight, product of:
               2.3142815 = boost
               3.159582 = idf(docFreq=5124, maxDocs=44421)
               0.020195791 = queryNorm
             0.6623475 = fieldWeight in 5548, product of:
               2.236068 = tf(freq=5.0), with freq of:
                 5.0 = termFreq=5.0
               3.159582 = idf(docFreq=5124, maxDocs=44421)
               0.09375 = fieldNorm(doc=5548)
         0.1901923 = weight(abstract_txt:planning in 5548) [ClassicSimilarity], result of:
           0.1901923 = score(doc=5548,freq=1.0), product of:
             0.33180326 = queryWeight, product of:
               2.6870687 = boost
               6.114219 = idf(docFreq=266, maxDocs=44421)
               0.020195791 = queryNorm
             0.57320803 = fieldWeight in 5548, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               6.114219 = idf(docFreq=266, maxDocs=44421)
               0.09375 = fieldNorm(doc=5548)
       0.24 = coord(6/25)