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Leydesdorff, L.; Opthof, T.: Scopus's source normalized impact per paper (SNIP) versus a journal impact factor based on fractional counting of citations (2010)
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- Abstract
- Impact factors (and similar measures such as the Scimago Journal Rankings) suffer from two problems: (a) citation behavior varies among fields of science and, therefore, leads to systematic differences, and (b) there are no statistics to inform us whether differences are significant. The recently introduced "source normalized impact per paper" indicator of Scopus tries to remedy the first of these two problems, but a number of normalization decisions are involved, which makes it impossible to test for significance. Using fractional counting of citations-based on the assumption that impact is proportionate to the number of references in the citing documents-citations can be contextualized at the paper level and aggregated impacts of sets can be tested for their significance. It can be shown that the weighted impact of Annals of Mathematics (0.247) is not so much lower than that of Molecular Cell (0.386) despite a five-f old difference between their impact factors (2.793 and 13.156, respectively).
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Leydesdorff, L.; Radicchi, F.; Bornmann, L.; Castellano, C.; Nooy, W. de: Field-normalized impact factors (IFs) : a comparison of rescaling and fractionally counted IFs (2013)
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Leydesdorff, L.; Moya-Anegón, F. de; Guerrero-Bote, V.P.: Journal maps, interactive overlays, and the measurement of interdisciplinarity on the basis of Scopus data (1996-2012) (2015)
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Leydesdorff, L.; Moya-Anegón, F. de; Nooy, W. de: Aggregated journal-journal citation relations in scopus and web of science matched and compared in terms of networks, maps, and interactive overlays (2016)
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Leydesdorff, L.; Wagner, C.S.; Porto-Gomez, I.; Comins, J.A.; Phillips, F.: Synergy in the knowledge base of U.S. innovation systems at national, state, and regional levels : the contributions of high-tech manufacturing and knowledge-intensive services (2019)
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Leydesdorff, L.; Perevodchikov, E.; Uvarov, A.: Measuring triple-helix synergy in the Russian innovation systems at regional, provincial, and national levels (2015)
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- Abstract
- We measure synergy for the Russian national, provincial, and regional innovation systems as reduction of uncertainty using mutual information among the 3 distributions of firm sizes, technological knowledge bases of firms, and geographical locations. Half a million units of data at firm level in 2011 were obtained from the OrbisT database of Bureau Van Dijk. The firm level data were aggregated at the levels of 8 Federal Districts, the regional level of 83 Federal Subjects, and the single level of the Russian Federation. Not surprisingly, the knowledge base of the economy is concentrated in the Moscow region (22.8%) and Saint Petersburg (4.0%). Except in Moscow itself, high-tech manufacturing does not add synergy to any other unit at any of the various levels of geographical granularity; instead it disturbs regional coordination. Knowledge-intensive services (KIS; including laboratories) contribute to the synergy in all Federal Districts (except the North-Caucasian Federal District), but only in 30 of the 83 Federal Subjects. The synergy in KIS is concentrated in centers of administration. The knowledge-intensive services (which are often state affiliated) provide backbone to an emerging knowledge-based economy at the level of Federal Districts, but the economy is otherwise not knowledge based (except for the Moscow region).
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Leydesdorff, L.; Bornmann, L.; Wagner, C.S.: ¬The relative influences of government funding and international collaboration on citation impact (2019)
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- Date
- 8. 1.2019 18:22:45
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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)
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- Date
- 22. 1.2011 12:51:07
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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)
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- Date
- 24. 8.2016 17:53:22
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Leydesdorff, L.; Johnson, M.W.; Ivanova, I.: Toward a calculus of redundancy : signification, codification, and anticipation in cultural evolution (2018)
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- Date
- 29. 9.2018 11:22:09
