Document (#39838)

Author

AlQenaei, Z.M.
Monarchi, D.E.

Title

¬The use of learning techniques to analyze the results of a manual classification system

Source

Knowledge organization. 43(2016) no.1, S.56-63

Year

2016

Abstract

Classification is the process of assigning objects to pre-defined classes based on observations or characteristics of those objects, and there are many approaches to performing this task. The overall objective of this study is to demonstrate the use of two learning techniques to analyze the results of a manual classification system. Our sample consisted of 1,026 documents, from the ACM Computing Classification System, classified by their authors as belonging to one of the groups of the classification system: "H.3 Information Storage and Retrieval." A singular value decomposition of the documents' weighted term-frequency matrix was used to represent each document in a 50-dimensional vector space. The analysis of the representation using both supervised (decision tree) and unsupervised (clustering) techniques suggests that two pairs of the ACM classes are closely related to each other in the vector space. Class 1 (Content Analysis and Indexing) is closely related to Class 3 (Information Search and Retrieval), and Class 4 (Systems and Software) is closely related to Class 5 (Online Information Services). Further analysis was performed to test the diffusion of the words in the two classes using both cosine and Euclidean distance.

Content

Vgl.: http://www.ergon-verlag.de/isko_ko/downloads/ko_43_2016_1_f.pdf.

Theme

Automatisches Klassifizieren

Object

Computing Classification System

Similar documents (content)

1. Li, T.; Zhu, S.; Ogihara, M.: Text categorization via generalized discriminant analysis (2008) 0.27

   0.26507512 = sum of:
     0.26507512 = product of:
       0.9466969 = sum of:
         0.08565683 = weight(abstract_txt:decomposition in 4120) [ClassicSimilarity], result of:
           0.08565683 = score(doc=4120,freq=1.0), product of:
             0.17344508 = queryWeight, product of:
               1.0393614 = boost
               7.9016905 = idf(docFreq=42, maxDocs=42740)
               0.021119101 = queryNorm
             0.49385566 = fieldWeight in 4120, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               7.9016905 = idf(docFreq=42, maxDocs=42740)
               0.0625 = fieldNorm(doc=4120)
         0.14578009 = weight(abstract_txt:singular in 4120) [ClassicSimilarity], result of:
           0.14578009 = score(doc=4120,freq=2.0), product of:
             0.19623484 = queryWeight, product of:
               1.1055379 = boost
               8.404794 = idf(docFreq=25, maxDocs=42740)
               0.021119101 = queryNorm
             0.7428858 = fieldWeight in 4120, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               8.404794 = idf(docFreq=25, maxDocs=42740)
               0.0625 = fieldNorm(doc=4120)
         0.02613499 = weight(abstract_txt:analysis in 4120) [ClassicSimilarity], result of:
           0.02613499 = score(doc=4120,freq=1.0), product of:
             0.113372914 = queryWeight, product of:
               1.455462 = boost
               3.6883576 = idf(docFreq=2905, maxDocs=42740)
               0.021119101 = queryNorm
             0.23052235 = fieldWeight in 4120, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.6883576 = idf(docFreq=2905, maxDocs=42740)
               0.0625 = fieldNorm(doc=4120)
         0.09604052 = weight(abstract_txt:vector in 4120) [ClassicSimilarity], result of:
           0.09604052 = score(doc=4120,freq=1.0), product of:
             0.23584878 = queryWeight, product of:
               1.714026 = boost
               6.515396 = idf(docFreq=171, maxDocs=42740)
               0.021119101 = queryNorm
             0.40721226 = fieldWeight in 4120, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               6.515396 = idf(docFreq=171, maxDocs=42740)
               0.0625 = fieldNorm(doc=4120)
         0.048278656 = weight(abstract_txt:techniques in 4120) [ClassicSimilarity], result of:
           0.048278656 = score(doc=4120,freq=1.0), product of:
             0.17068598 = queryWeight, product of:
               1.7858506 = boost
               4.525612 = idf(docFreq=1257, maxDocs=42740)
               0.021119101 = queryNorm
             0.28285074 = fieldWeight in 4120, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.525612 = idf(docFreq=1257, maxDocs=42740)
               0.0625 = fieldNorm(doc=4120)
         0.16667017 = weight(abstract_txt:classification in 4120) [ClassicSimilarity], result of:
           0.16667017 = score(doc=4120,freq=9.0), product of:
             0.22222951 = queryWeight, product of:
               2.6307006 = boost
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.021119101 = queryNorm
             0.7499912 = fieldWeight in 4120, product of:
               3.0 = tf(freq=9.0), with freq of:
                 9.0 = termFreq=9.0
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.0625 = fieldNorm(doc=4120)
         0.37813562 = weight(abstract_txt:class in 4120) [ClassicSimilarity], result of:
           0.37813562 = score(doc=4120,freq=7.0), product of:
             0.38732278 = queryWeight, product of:
               3.106362 = boost
               5.903989 = idf(docFreq=316, maxDocs=42740)
               0.021119101 = queryNorm
             0.97628033 = fieldWeight in 4120, product of:
               2.6457512 = tf(freq=7.0), with freq of:
                 7.0 = termFreq=7.0
               5.903989 = idf(docFreq=316, maxDocs=42740)
               0.0625 = fieldNorm(doc=4120)
       0.28 = coord(7/25)
   

2. Lochbaum, K.E.; Streeter, A.R.: Comparing and combining the effectiveness of latent semantic indexing and the ordinary vector space model for information retrieval (1989) 0.23

   0.22977768 = sum of:
     0.22977768 = product of:
       0.71805525 = sum of:
         0.15142132 = weight(abstract_txt:decomposition in 4459) [ClassicSimilarity], result of:
           0.15142132 = score(doc=4459,freq=2.0), product of:
             0.17344508 = queryWeight, product of:
               1.0393614 = boost
               7.9016905 = idf(docFreq=42, maxDocs=42740)
               0.021119101 = queryNorm
             0.8730217 = fieldWeight in 4459, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               7.9016905 = idf(docFreq=42, maxDocs=42740)
               0.078125 = fieldNorm(doc=4459)
         0.052400477 = weight(abstract_txt:documents in 4459) [ClassicSimilarity], result of:
           0.052400477 = score(doc=4459,freq=3.0), product of:
             0.09409656 = queryWeight, product of:
               1.0826484 = boost
               4.115389 = idf(docFreq=1895, maxDocs=42740)
               0.021119101 = queryNorm
             0.5568799 = fieldWeight in 4459, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               4.115389 = idf(docFreq=1895, maxDocs=42740)
               0.078125 = fieldNorm(doc=4459)
         0.1288526 = weight(abstract_txt:singular in 4459) [ClassicSimilarity], result of:
           0.1288526 = score(doc=4459,freq=1.0), product of:
             0.19623484 = queryWeight, product of:
               1.1055379 = boost
               8.404794 = idf(docFreq=25, maxDocs=42740)
               0.021119101 = queryNorm
             0.6566245 = fieldWeight in 4459, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.404794 = idf(docFreq=25, maxDocs=42740)
               0.078125 = fieldNorm(doc=4459)
         0.13636816 = weight(abstract_txt:space in 4459) [ClassicSimilarity], result of:
           0.13636816 = score(doc=4459,freq=4.0), product of:
             0.16175061 = queryWeight, product of:
               1.4194613 = boost
               5.39569 = idf(docFreq=526, maxDocs=42740)
               0.021119101 = queryNorm
             0.8430766 = fieldWeight in 4459, product of:
               2.0 = tf(freq=4.0), with freq of:
                 4.0 = termFreq=4.0
               5.39569 = idf(docFreq=526, maxDocs=42740)
               0.078125 = fieldNorm(doc=4459)
         0.03266874 = weight(abstract_txt:analysis in 4459) [ClassicSimilarity], result of:
           0.03266874 = score(doc=4459,freq=1.0), product of:
             0.113372914 = queryWeight, product of:
               1.455462 = boost
               3.6883576 = idf(docFreq=2905, maxDocs=42740)
               0.021119101 = queryNorm
             0.28815293 = fieldWeight in 4459, 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=4459)
         0.049583714 = weight(abstract_txt:related in 4459) [ClassicSimilarity], result of:
           0.049583714 = score(doc=4459,freq=1.0), product of:
             0.1497317 = queryWeight, product of:
               1.6726422 = boost
               4.238725 = idf(docFreq=1675, maxDocs=42740)
               0.021119101 = queryNorm
             0.3311504 = fieldWeight in 4459, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.238725 = idf(docFreq=1675, maxDocs=42740)
               0.078125 = fieldNorm(doc=4459)
         0.12005065 = weight(abstract_txt:vector in 4459) [ClassicSimilarity], result of:
           0.12005065 = score(doc=4459,freq=1.0), product of:
             0.23584878 = queryWeight, product of:
               1.714026 = boost
               6.515396 = idf(docFreq=171, maxDocs=42740)
               0.021119101 = queryNorm
             0.5090153 = fieldWeight in 4459, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               6.515396 = idf(docFreq=171, maxDocs=42740)
               0.078125 = fieldNorm(doc=4459)
         0.04670953 = weight(abstract_txt:system in 4459) [ClassicSimilarity], result of:
           0.04670953 = score(doc=4459,freq=2.0), product of:
             0.12569779 = queryWeight, product of:
               1.7696174 = boost
               3.3633559 = idf(docFreq=4021, maxDocs=42740)
               0.021119101 = queryNorm
             0.37160185 = fieldWeight in 4459, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.3633559 = idf(docFreq=4021, maxDocs=42740)
               0.078125 = fieldNorm(doc=4459)
       0.32 = coord(8/25)
   

3. Xu, L.; Qiu, J.: Unsupervised multi-class sentiment classification approach (2019) 0.22

   0.2178903 = sum of:
     0.2178903 = product of:
       0.77817965 = sum of:
         0.07681383 = weight(abstract_txt:supervised in 1004) [ClassicSimilarity], result of:
           0.07681383 = score(doc=1004,freq=1.0), product of:
             0.16129228 = queryWeight, product of:
               1.0022876 = boost
               7.619839 = idf(docFreq=56, maxDocs=42740)
               0.021119101 = queryNorm
             0.47623995 = fieldWeight in 1004, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               7.619839 = idf(docFreq=56, maxDocs=42740)
               0.0625 = fieldNorm(doc=1004)
         0.11016596 = weight(abstract_txt:unsupervised in 1004) [ClassicSimilarity], result of:
           0.11016596 = score(doc=1004,freq=2.0), product of:
             0.16280796 = queryWeight, product of:
               1.0069859 = boost
               7.655557 = idf(docFreq=54, maxDocs=42740)
               0.021119101 = queryNorm
             0.676662 = fieldWeight in 1004, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               7.655557 = idf(docFreq=54, maxDocs=42740)
               0.0625 = fieldNorm(doc=1004)
         0.024513848 = weight(abstract_txt:each in 1004) [ClassicSimilarity], result of:
           0.024513848 = score(doc=1004,freq=1.0), product of:
             0.09490119 = queryWeight, product of:
               1.0872675 = boost
               4.132947 = idf(docFreq=1862, maxDocs=42740)
               0.021119101 = queryNorm
             0.2583092 = fieldWeight in 1004, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.132947 = idf(docFreq=1862, maxDocs=42740)
               0.0625 = fieldNorm(doc=1004)
         0.02613499 = weight(abstract_txt:analysis in 1004) [ClassicSimilarity], result of:
           0.02613499 = score(doc=1004,freq=1.0), product of:
             0.113372914 = queryWeight, product of:
               1.455462 = boost
               3.6883576 = idf(docFreq=2905, maxDocs=42740)
               0.021119101 = queryNorm
             0.23052235 = fieldWeight in 1004, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.6883576 = idf(docFreq=2905, maxDocs=42740)
               0.0625 = fieldNorm(doc=1004)
         0.07397879 = weight(abstract_txt:manual in 1004) [ClassicSimilarity], result of:
           0.07397879 = score(doc=1004,freq=1.0), product of:
             0.1981841 = queryWeight, product of:
               1.5712126 = boost
               5.972531 = idf(docFreq=295, maxDocs=42740)
               0.021119101 = queryNorm
             0.37328318 = fieldWeight in 1004, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.972531 = idf(docFreq=295, maxDocs=42740)
               0.0625 = fieldNorm(doc=1004)
         0.14698927 = weight(abstract_txt:classification in 1004) [ClassicSimilarity], result of:
           0.14698927 = score(doc=1004,freq=7.0), product of:
             0.22222951 = queryWeight, product of:
               2.6307006 = boost
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.021119101 = queryNorm
             0.66143 = fieldWeight in 1004, product of:
               2.6457512 = tf(freq=7.0), with freq of:
                 7.0 = termFreq=7.0
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.0625 = fieldNorm(doc=1004)
         0.31958294 = weight(abstract_txt:class in 1004) [ClassicSimilarity], result of:
           0.31958294 = score(doc=1004,freq=5.0), product of:
             0.38732278 = queryWeight, product of:
               3.106362 = boost
               5.903989 = idf(docFreq=316, maxDocs=42740)
               0.021119101 = queryNorm
             0.8251075 = fieldWeight in 1004, product of:
               2.236068 = tf(freq=5.0), with freq of:
                 5.0 = termFreq=5.0
               5.903989 = idf(docFreq=316, maxDocs=42740)
               0.0625 = fieldNorm(doc=1004)
       0.28 = coord(7/25)
   

4. Needham, R.M.; Sparck Jones, K.: Keywords and clumps (1985) 0.21

   0.21087077 = sum of:
     0.21087077 = product of:
       0.5857521 = sum of:
         0.026200239 = weight(abstract_txt:documents in 4646) [ClassicSimilarity], result of:
           0.026200239 = score(doc=4646,freq=3.0), product of:
             0.09409656 = queryWeight, product of:
               1.0826484 = boost
               4.115389 = idf(docFreq=1895, maxDocs=42740)
               0.021119101 = queryNorm
             0.27843994 = fieldWeight in 4646, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               4.115389 = idf(docFreq=1895, maxDocs=42740)
               0.0390625 = fieldNorm(doc=4646)
         0.021667385 = weight(abstract_txt:each in 4646) [ClassicSimilarity], result of:
           0.021667385 = score(doc=4646,freq=2.0), product of:
             0.09490119 = queryWeight, product of:
               1.0872675 = boost
               4.132947 = idf(docFreq=1862, maxDocs=42740)
               0.021119101 = queryNorm
             0.22831522 = fieldWeight in 4646, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.132947 = idf(docFreq=1862, maxDocs=42740)
               0.0390625 = fieldNorm(doc=4646)
         0.05064588 = weight(abstract_txt:objects in 4646) [ClassicSimilarity], result of:
           0.05064588 = score(doc=4646,freq=2.0), product of:
             0.1671463 = queryWeight, product of:
               1.4429423 = boost
               5.4849463 = idf(docFreq=481, maxDocs=42740)
               0.021119101 = queryNorm
             0.3030033 = fieldWeight in 4646, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               5.4849463 = idf(docFreq=481, maxDocs=42740)
               0.0390625 = fieldNorm(doc=4646)
         0.046236742 = weight(abstract_txt:manual in 4646) [ClassicSimilarity], result of:
           0.046236742 = score(doc=4646,freq=1.0), product of:
             0.1981841 = queryWeight, product of:
               1.5712126 = boost
               5.972531 = idf(docFreq=295, maxDocs=42740)
               0.021119101 = queryNorm
             0.23330198 = fieldWeight in 4646, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.972531 = idf(docFreq=295, maxDocs=42740)
               0.0390625 = fieldNorm(doc=4646)
         0.03506098 = weight(abstract_txt:related in 4646) [ClassicSimilarity], result of:
           0.03506098 = score(doc=4646,freq=2.0), product of:
             0.1497317 = queryWeight, product of:
               1.6726422 = boost
               4.238725 = idf(docFreq=1675, maxDocs=42740)
               0.021119101 = queryNorm
             0.2341587 = fieldWeight in 4646, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.238725 = idf(docFreq=1675, maxDocs=42740)
               0.0390625 = fieldNorm(doc=4646)
         0.03017416 = weight(abstract_txt:techniques in 4646) [ClassicSimilarity], result of:
           0.03017416 = score(doc=4646,freq=1.0), product of:
             0.17068598 = queryWeight, product of:
               1.7858506 = boost
               4.525612 = idf(docFreq=1257, maxDocs=42740)
               0.021119101 = queryNorm
             0.17678171 = fieldWeight in 4646, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.525612 = idf(docFreq=1257, maxDocs=42740)
               0.0390625 = fieldNorm(doc=4646)
         0.17179762 = weight(abstract_txt:classes in 4646) [ClassicSimilarity], result of:
           0.17179762 = score(doc=4646,freq=7.0), product of:
             0.28450274 = queryWeight, product of:
               2.305629 = boost
               5.842808 = idf(docFreq=336, maxDocs=42740)
               0.021119101 = queryNorm
             0.6038522 = fieldWeight in 4646, product of:
               2.6457512 = tf(freq=7.0), with freq of:
                 7.0 = termFreq=7.0
               5.842808 = idf(docFreq=336, maxDocs=42740)
               0.0390625 = fieldNorm(doc=4646)
         0.07764288 = weight(abstract_txt:classification in 4646) [ClassicSimilarity], result of:
           0.07764288 = score(doc=4646,freq=5.0), product of:
             0.22222951 = queryWeight, product of:
               2.6307006 = boost
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.021119101 = queryNorm
             0.3493815 = fieldWeight in 4646, product of:
               2.236068 = tf(freq=5.0), with freq of:
                 5.0 = termFreq=5.0
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.0390625 = fieldNorm(doc=4646)
         0.12632625 = weight(abstract_txt:class in 4646) [ClassicSimilarity], result of:
           0.12632625 = score(doc=4646,freq=2.0), product of:
             0.38732278 = queryWeight, product of:
               3.106362 = boost
               5.903989 = idf(docFreq=316, maxDocs=42740)
               0.021119101 = queryNorm
             0.32615238 = fieldWeight in 4646, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               5.903989 = idf(docFreq=316, maxDocs=42740)
               0.0390625 = fieldNorm(doc=4646)
       0.36 = coord(9/25)
   

5. Borodin, Y.; Polishchuk, V.; Mahmud, J.; Ramakrishnan, I.V.; Stent, A.: Live and learn from mistakes : a lightweight system for document classification (2013) 0.21

   0.20690405 = sum of:
     0.20690405 = product of:
       0.73894304 = sum of:
         0.041920386 = weight(abstract_txt:documents in 4723) [ClassicSimilarity], result of:
           0.041920386 = score(doc=4723,freq=3.0), product of:
             0.09409656 = queryWeight, product of:
               1.0826484 = boost
               4.115389 = idf(docFreq=1895, maxDocs=42740)
               0.021119101 = queryNorm
             0.44550392 = fieldWeight in 4723, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               4.115389 = idf(docFreq=1895, maxDocs=42740)
               0.0625 = fieldNorm(doc=4723)
         0.086272016 = weight(abstract_txt:learning in 4723) [ClassicSimilarity], result of:
           0.086272016 = score(doc=4723,freq=5.0), product of:
             0.12840658 = queryWeight, product of:
               1.2647195 = boost
               4.807482 = idf(docFreq=948, maxDocs=42740)
               0.021119101 = queryNorm
             0.671866 = fieldWeight in 4723, product of:
               2.236068 = tf(freq=5.0), with freq of:
                 5.0 = termFreq=5.0
               4.807482 = idf(docFreq=948, maxDocs=42740)
               0.0625 = fieldNorm(doc=4723)
         0.05454726 = weight(abstract_txt:space in 4723) [ClassicSimilarity], result of:
           0.05454726 = score(doc=4723,freq=1.0), product of:
             0.16175061 = queryWeight, product of:
               1.4194613 = boost
               5.39569 = idf(docFreq=526, maxDocs=42740)
               0.021119101 = queryNorm
             0.33723062 = fieldWeight in 4723, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.39569 = idf(docFreq=526, maxDocs=42740)
               0.0625 = fieldNorm(doc=4723)
         0.09604052 = weight(abstract_txt:vector in 4723) [ClassicSimilarity], result of:
           0.09604052 = score(doc=4723,freq=1.0), product of:
             0.23584878 = queryWeight, product of:
               1.714026 = boost
               6.515396 = idf(docFreq=171, maxDocs=42740)
               0.021119101 = queryNorm
             0.40721226 = fieldWeight in 4723, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               6.515396 = idf(docFreq=171, maxDocs=42740)
               0.0625 = fieldNorm(doc=4723)
         0.14692749 = weight(abstract_txt:classes in 4723) [ClassicSimilarity], result of:
           0.14692749 = score(doc=4723,freq=2.0), product of:
             0.28450274 = queryWeight, product of:
               2.305629 = boost
               5.842808 = idf(docFreq=336, maxDocs=42740)
               0.021119101 = queryNorm
             0.5164361 = fieldWeight in 4723, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               5.842808 = idf(docFreq=336, maxDocs=42740)
               0.0625 = fieldNorm(doc=4723)
         0.111113444 = weight(abstract_txt:classification in 4723) [ClassicSimilarity], result of:
           0.111113444 = score(doc=4723,freq=4.0), product of:
             0.22222951 = queryWeight, product of:
               2.6307006 = boost
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.021119101 = queryNorm
             0.4999941 = fieldWeight in 4723, product of:
               2.0 = tf(freq=4.0), with freq of:
                 4.0 = termFreq=4.0
               3.9999528 = idf(docFreq=2127, maxDocs=42740)
               0.0625 = fieldNorm(doc=4723)
         0.20212199 = weight(abstract_txt:class in 4723) [ClassicSimilarity], result of:
           0.20212199 = score(doc=4723,freq=2.0), product of:
             0.38732278 = queryWeight, product of:
               3.106362 = boost
               5.903989 = idf(docFreq=316, maxDocs=42740)
               0.021119101 = queryNorm
             0.5218438 = fieldWeight in 4723, 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=4723)
       0.28 = coord(7/25)