-
Leydesdorff, L.; Salah, A.A.A.: Maps on the basis of the Arts & Humanities Citation Index : the journals Leonardo and Art Journal versus "digital humanities" as a topic (2010)
0.02
0.018278074 = product of:
0.073112294 = sum of:
0.073112294 = weight(_text_:digital in 3436) [ClassicSimilarity], result of:
0.073112294 = score(doc=3436,freq=4.0), product of:
0.19770671 = queryWeight, product of:
3.944552 = idf(docFreq=2326, maxDocs=44218)
0.050121464 = queryNorm
0.36980176 = fieldWeight in 3436, product of:
2.0 = tf(freq=4.0), with freq of:
4.0 = termFreq=4.0
3.944552 = idf(docFreq=2326, maxDocs=44218)
0.046875 = fieldNorm(doc=3436)
0.25 = coord(1/4)
- Abstract
- The possibilities of using the Arts & Humanities Citation Index (A&HCI) for journal mapping have not been sufficiently recognized because of the absence of a Journal Citations Report (JCR) for this database. A quasi-JCR for the A&HCI ([2008]) was constructed from the data contained in the Web of Science and is used for the evaluation of two journals as examples: Leonardo and Art Journal. The maps on the basis of the aggregated journal-journal citations within this domain can be compared with maps including references to journals in the Science Citation Index and Social Science Citation Index. Art journals are cited by (social) science journals more than by other art journals, but these journals draw upon one another in terms of their own references. This cultural impact in terms of being cited is not found when documents with a topic such as digital humanities are analyzed. This community of practice functions more as an intellectual organizer than a journal.
-
Bensman, S.J.; Leydesdorff, L.: Definition and identification of journals as bibliographic and subject entities : librarianship versus ISI Journal Citation Reports methods and their effect on citation measures (2009)
0.01
0.009946881 = product of:
0.039787523 = sum of:
0.039787523 = weight(_text_:library in 2840) [ClassicSimilarity], result of:
0.039787523 = score(doc=2840,freq=6.0), product of:
0.1317883 = queryWeight, product of:
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.050121464 = queryNorm
0.30190483 = fieldWeight in 2840, product of:
2.4494898 = tf(freq=6.0), with freq of:
6.0 = termFreq=6.0
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.046875 = fieldNorm(doc=2840)
0.25 = coord(1/4)
- Abstract
- This paper explores the ISI Journal Citation Reports (JCR) bibliographic and subject structures through Library of Congress (LC) and American research libraries cataloging and classification methodology. The 2006 Science Citation Index JCR Behavioral Sciences subject category journals are used as an example. From the library perspective, the main fault of the JCR bibliographic structure is that the JCR mistakenly identifies journal title segments as journal bibliographic entities, seriously affecting journal rankings by total cites and the impact factor. In respect to JCR subject structure, the title segment, which constitutes the JCR bibliographic basis, is posited as the best bibliographic entity for the citation measurement of journal subject relationships. Through factor analysis and other methods, the JCR subject categorization of journals is tested against their LC subject headings and classification. The finding is that JCR and library journal subject analyses corroborate, clarify, and correct each other.
-
Leydesdorff, L.; Bornmann, L.: ¬The operationalization of "fields" as WoS subject categories (WCs) in evaluative bibliometrics : the cases of "library and information science" and "science & technology studies" (2016)
0.01
0.008121594 = product of:
0.032486375 = sum of:
0.032486375 = weight(_text_:library in 2779) [ClassicSimilarity], result of:
0.032486375 = score(doc=2779,freq=4.0), product of:
0.1317883 = queryWeight, product of:
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.050121464 = queryNorm
0.24650425 = fieldWeight in 2779, product of:
2.0 = tf(freq=4.0), with freq of:
4.0 = termFreq=4.0
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.046875 = fieldNorm(doc=2779)
0.25 = coord(1/4)
- Abstract
- Normalization of citation scores using reference sets based on Web of Science subject categories (WCs) has become an established ("best") practice in evaluative bibliometrics. For example, the Times Higher Education World University Rankings are, among other things, based on this operationalization. However, WCs were developed decades ago for the purpose of information retrieval and evolved incrementally with the database; the classification is machine-based and partially manually corrected. Using the WC "information science & library science" and the WCs attributed to journals in the field of "science and technology studies," we show that WCs do not provide sufficient analytical clarity to carry bibliometric normalization in evaluation practices because of "indexer effects." Can the compliance with "best practices" be replaced with an ambition to develop "best possible practices"? New research questions can then be envisaged.
-
Leydesdorff, L.; Bornmann, L.: Integrated impact indicators compared with impact factors : an alternative research design with policy implications (2011)
0.01
0.0067679947 = product of:
0.027071979 = sum of:
0.027071979 = weight(_text_:library in 4919) [ClassicSimilarity], result of:
0.027071979 = score(doc=4919,freq=4.0), product of:
0.1317883 = queryWeight, product of:
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.050121464 = queryNorm
0.2054202 = fieldWeight in 4919, product of:
2.0 = tf(freq=4.0), with freq of:
4.0 = termFreq=4.0
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.0390625 = fieldNorm(doc=4919)
0.25 = coord(1/4)
- Abstract
- In bibliometrics, the association of "impact" with central-tendency statistics is mistaken. Impacts add up, and citation curves therefore should be integrated instead of averaged. For example, the journals MIS Quarterly and Journal of the American Society for Information Science and Technology differ by a factor of 2 in terms of their respective impact factors (IF), but the journal with the lower IF has the higher impact. Using percentile ranks (e.g., top-1%, top-10%, etc.), an Integrated Impact Indicator (I3) can be based on integration of the citation curves, but after normalization of the citation curves to the same scale. The results across document sets can be compared as percentages of the total impact of a reference set. Total number of citations, however, should not be used instead because the shape of the citation curves is then not appreciated. I3 can be applied to any document set and any citation window. The results of the integration (summation) are fully decomposable in terms of journals or institutional units such as nations, universities, and so on because percentile ranks are determined at the paper level. In this study, we first compare I3 with IFs for the journals in two Institute for Scientific Information subject categories ("Information Science & Library Science" and "Multidisciplinary Sciences"). The library and information science set is additionally decomposed in terms of nations. Policy implications of this possible paradigm shift in citation impact analysis are specified.
-
Bauer, J.; Leydesdorff, L.; Bornmann, L.: Highly cited papers in Library and Information Science (LIS) : authors, institutions, and network structures (2016)
0.01
0.0067679947 = product of:
0.027071979 = sum of:
0.027071979 = weight(_text_:library in 3231) [ClassicSimilarity], result of:
0.027071979 = score(doc=3231,freq=4.0), product of:
0.1317883 = queryWeight, product of:
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.050121464 = queryNorm
0.2054202 = fieldWeight in 3231, product of:
2.0 = tf(freq=4.0), with freq of:
4.0 = termFreq=4.0
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.0390625 = fieldNorm(doc=3231)
0.25 = coord(1/4)
- Abstract
- As a follow-up to the highly cited authors list published by Thomson Reuters in June 2014, we analyzed the top 1% most frequently cited papers published between 2002 and 2012 included in the Web of Science (WoS) subject category "Information Science & Library Science." In all, 798 authors contributed to 305 top 1% publications; these authors were employed at 275 institutions. The authors at Harvard University contributed the largest number of papers, when the addresses are whole-number counted. However, Leiden University leads the ranking if fractional counting is used. Twenty-three of the 798 authors were also listed as most highly cited authors by Thomson Reuters in June 2014 (http://highlycited.com/). Twelve of these 23 authors were involved in publishing 4 or more of the 305 papers under study. Analysis of coauthorship relations among the 798 highly cited scientists shows that coauthorships are based on common interests in a specific topic. Three topics were important between 2002 and 2012: (a) collection and exploitation of information in clinical practices; (b) use of the Internet in public communication and commerce; and (c) scientometrics.
-
Zhou, P.; Su, X.; Leydesdorff, L.: ¬A comparative study on communication structures of Chinese journals in the social sciences (2010)
0.01
0.0057428335 = product of:
0.022971334 = sum of:
0.022971334 = weight(_text_:library in 3580) [ClassicSimilarity], result of:
0.022971334 = score(doc=3580,freq=2.0), product of:
0.1317883 = queryWeight, product of:
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.050121464 = queryNorm
0.17430481 = fieldWeight in 3580, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.046875 = fieldNorm(doc=3580)
0.25 = coord(1/4)
- Abstract
- We argue that the communication structures in the Chinese social sciences have not yet been sufficiently reformed. Citation patterns among Chinese domestic journals in three subject areas - political science and Marxism, library and information science, and economics - are compared with their counterparts internationally. Like their colleagues in the natural and life sciences, Chinese scholars in the social sciences provide fewer references to journal publications than their international counterparts; like their international colleagues, social scientists provide fewer references than natural sciences. The resulting citation networks, therefore, are sparse. Nevertheless, the citation structures clearly suggest that the Chinese social sciences are far less specialized in terms of disciplinary delineations than their international counterparts. Marxism studies are more established than political science in China. In terms of the impact of the Chinese political system on academic fields, disciplines closely related to the political system are less specialized than those weakly related. In the discussion section, we explore reasons that may cause the current stagnation and provide policy recommendations.
-
Rafols, I.; Porter, A.L.; Leydesdorff, L.: Science overlay maps : a new tool for research policy and library management (2010)
0.01
0.0057428335 = product of:
0.022971334 = sum of:
0.022971334 = weight(_text_:library in 3987) [ClassicSimilarity], result of:
0.022971334 = score(doc=3987,freq=2.0), product of:
0.1317883 = queryWeight, product of:
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.050121464 = queryNorm
0.17430481 = fieldWeight in 3987, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.046875 = fieldNorm(doc=3987)
0.25 = coord(1/4)
-
Zhou, Q.; Leydesdorff, L.: ¬The normalization of occurrence and co-occurrence matrices in bibliometrics using Cosine similarities and Ochiai coefficients (2016)
0.01
0.0057428335 = product of:
0.022971334 = sum of:
0.022971334 = weight(_text_:library in 3161) [ClassicSimilarity], result of:
0.022971334 = score(doc=3161,freq=2.0), product of:
0.1317883 = queryWeight, product of:
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.050121464 = queryNorm
0.17430481 = fieldWeight in 3161, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.046875 = fieldNorm(doc=3161)
0.25 = coord(1/4)
- Abstract
- We prove that Ochiai similarity of the co-occurrence matrix is equal to cosine similarity in the underlying occurrence matrix. Neither the cosine nor the Pearson correlation should be used for the normalization of co-occurrence matrices because the similarity is then normalized twice, and therefore overestimated; the Ochiai coefficient can be used instead. Results are shown using a small matrix (5 cases, 4 variables) for didactic reasons, and also Ahlgren et?al.'s (2003) co-occurrence matrix of 24 authors in library and information sciences. The overestimation is shown numerically and will be illustrated using multidimensional scaling and cluster dendograms. If the occurrence matrix is not available (such as in internet research or author cocitation analysis) using Ochiai for the normalization is preferable to using the cosine.
-
Comins, J.A.; Leydesdorff, L.: Identification of long-term concept-symbols among citations : do common intellectual histories structure citation behavior? (2017)
0.01
0.0057428335 = product of:
0.022971334 = sum of:
0.022971334 = weight(_text_:library in 3599) [ClassicSimilarity], result of:
0.022971334 = score(doc=3599,freq=2.0), product of:
0.1317883 = queryWeight, product of:
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.050121464 = queryNorm
0.17430481 = fieldWeight in 3599, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
2.6293786 = idf(docFreq=8668, maxDocs=44218)
0.046875 = fieldNorm(doc=3599)
0.25 = coord(1/4)
- Abstract
- "Citation classics" are not only highly cited, but also cited during several decades. We explore whether the peaks in the spectrograms generated by Reference Publication Years Spectroscopy (RPYS) indicate such long-term impact by comparing across RPYS for subsequent time intervals. Multi-RPYS enables us to distinguish between short-term citation peaks at the research front that decay within 10 years versus historically constitutive (long-term) citations that function as concept symbols. Using these constitutive citations, one is able to cluster document sets (e.g., journals) in terms of intellectually shared histories. We test this premise by clustering 40 journals in the Web of Science Category of Information and Library Science using multi-RPYS. It follows that RPYS can not only be used for retrieving roots of sets under study (cited), but also for algorithmic historiography of the citing sets. Significant references are historically rooted symbols among other citations that function as currency.
-
Leydesdorff, L.: ¬The construction and globalization of the knowledge base in inter-human communication systems (2003)
0.01
0.005093075 = product of:
0.0203723 = sum of:
0.0203723 = product of:
0.0407446 = sum of:
0.0407446 = weight(_text_:22 in 1621) [ClassicSimilarity], result of:
0.0407446 = score(doc=1621,freq=2.0), product of:
0.17551683 = queryWeight, product of:
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.050121464 = queryNorm
0.23214069 = fieldWeight in 1621, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.046875 = fieldNorm(doc=1621)
0.5 = coord(1/2)
0.25 = coord(1/4)
- Date
- 22. 5.2003 19:48:04
-
Leydesdorff, L.: Can networks of journal-journal citations be used as indicators of change in the social sciences? (2003)
0.01
0.005093075 = product of:
0.0203723 = sum of:
0.0203723 = product of:
0.0407446 = sum of:
0.0407446 = weight(_text_:22 in 4460) [ClassicSimilarity], result of:
0.0407446 = score(doc=4460,freq=2.0), product of:
0.17551683 = queryWeight, product of:
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.050121464 = queryNorm
0.23214069 = fieldWeight in 4460, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.046875 = fieldNorm(doc=4460)
0.5 = coord(1/2)
0.25 = coord(1/4)
- Date
- 6.11.2005 19:02:22
-
Leydesdorff, L.; Sun, Y.: National and international dimensions of the Triple Helix in Japan : university-industry-government versus international coauthorship relations (2009)
0.01
0.005093075 = product of:
0.0203723 = sum of:
0.0203723 = product of:
0.0407446 = sum of:
0.0407446 = weight(_text_:22 in 2761) [ClassicSimilarity], result of:
0.0407446 = score(doc=2761,freq=2.0), product of:
0.17551683 = queryWeight, product of:
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.050121464 = queryNorm
0.23214069 = fieldWeight in 2761, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.046875 = fieldNorm(doc=2761)
0.5 = coord(1/2)
0.25 = coord(1/4)
- Date
- 22. 3.2009 19:07:20
-
Leydesdorff, L.; Bornmann, L.; Wagner, C.S.: ¬The relative influences of government funding and international collaboration on citation impact (2019)
0.01
0.005093075 = product of:
0.0203723 = sum of:
0.0203723 = product of:
0.0407446 = sum of:
0.0407446 = weight(_text_:22 in 4681) [ClassicSimilarity], result of:
0.0407446 = score(doc=4681,freq=2.0), product of:
0.17551683 = queryWeight, product of:
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.050121464 = queryNorm
0.23214069 = fieldWeight in 4681, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.046875 = fieldNorm(doc=4681)
0.5 = coord(1/2)
0.25 = coord(1/4)
- Date
- 8. 1.2019 18:22:45
-
Leydesdorff, L.; Bornmann, L.: How fractional counting of citations affects the impact factor : normalization in terms of differences in citation potentials among fields of science (2011)
0.00
0.0042442293 = product of:
0.016976917 = sum of:
0.016976917 = product of:
0.033953834 = sum of:
0.033953834 = weight(_text_:22 in 4186) [ClassicSimilarity], result of:
0.033953834 = score(doc=4186,freq=2.0), product of:
0.17551683 = queryWeight, product of:
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.050121464 = queryNorm
0.19345059 = fieldWeight in 4186, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.0390625 = fieldNorm(doc=4186)
0.5 = coord(1/2)
0.25 = coord(1/4)
- Date
- 22. 1.2011 12:51:07
-
Hellsten, I.; Leydesdorff, L.: ¬The construction of interdisciplinarity : the development of the knowledge base and programmatic focus of the journal Climatic Change, 1977-2013 (2016)
0.00
0.0042442293 = product of:
0.016976917 = sum of:
0.016976917 = product of:
0.033953834 = sum of:
0.033953834 = weight(_text_:22 in 3089) [ClassicSimilarity], result of:
0.033953834 = score(doc=3089,freq=2.0), product of:
0.17551683 = queryWeight, product of:
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.050121464 = queryNorm
0.19345059 = fieldWeight in 3089, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.0390625 = fieldNorm(doc=3089)
0.5 = coord(1/2)
0.25 = coord(1/4)
- Date
- 24. 8.2016 17:53:22
-
Leydesdorff, L.; Johnson, M.W.; Ivanova, I.: Toward a calculus of redundancy : signification, codification, and anticipation in cultural evolution (2018)
0.00
0.0042442293 = product of:
0.016976917 = sum of:
0.016976917 = product of:
0.033953834 = sum of:
0.033953834 = weight(_text_:22 in 4463) [ClassicSimilarity], result of:
0.033953834 = score(doc=4463,freq=2.0), product of:
0.17551683 = queryWeight, product of:
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.050121464 = queryNorm
0.19345059 = fieldWeight in 4463, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.0390625 = fieldNorm(doc=4463)
0.5 = coord(1/2)
0.25 = coord(1/4)
- Date
- 29. 9.2018 11:22:09
