Search (14 results, page 1 of 1)

Leydesdorff, L.; Bornmann, L.; Wagner, C.S.: ¬The relative influences of government funding and international collaboration on citation impact (2019) 0.04
```
0.036295015 = product of:
  0.07259003 = sum of:
    0.07259003 = sum of:
      0.029974142 = weight(_text_:2 in 4681) [ClassicSimilarity], result of:
        0.029974142 = score(doc=4681,freq=4.0), product of:
          0.1294644 = queryWeight, product of:
            2.4695914 = idf(docFreq=10170, maxDocs=44218)
            0.05242341 = queryNorm
          0.2315242 = fieldWeight in 4681, product of:
            2.0 = tf(freq=4.0), with freq of:
              4.0 = termFreq=4.0
            2.4695914 = idf(docFreq=10170, maxDocs=44218)
            0.046875 = fieldNorm(doc=4681)
      0.04261589 = weight(_text_:22 in 4681) [ClassicSimilarity], result of:
        0.04261589 = score(doc=4681,freq=2.0), product of:
          0.18357785 = queryWeight, product of:
            3.5018296 = idf(docFreq=3622, maxDocs=44218)
            0.05242341 = 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)
```
Abstract

A recent publication in Nature reports that public R&D funding is only weakly correlated with the citation impact of a nation's articles as measured by the field-weighted citation index (FWCI; defined by Scopus). On the basis of the supplementary data, we up-scaled the design using Web of Science data for the decade 2003-2013 and OECD funding data for the corresponding decade assuming a 2-year delay (2001-2011). Using negative binomial regression analysis, we found very small coefficients, but the effects of international collaboration are positive and statistically significant, whereas the effects of government funding are negative, an order of magnitude smaller, and statistically nonsignificant (in two of three analyses). In other words, international collaboration improves the impact of research articles, whereas more government funding tends to have a small adverse effect when comparing OECD countries.

Date

8. 1.2019 18:22:45

Source

Journal of the Association for Information Science and Technology. 70(2019) no.2, S.198-201

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) 0.03

0.026587836 = product of:
  0.053175673 = sum of:
    0.053175673 = sum of:
      0.017662432 = weight(_text_:2 in 4186) [ClassicSimilarity], result of:
        0.017662432 = score(doc=4186,freq=2.0), product of:
          0.1294644 = queryWeight, product of:
            2.4695914 = idf(docFreq=10170, maxDocs=44218)
            0.05242341 = queryNorm
          0.13642694 = fieldWeight in 4186, product of:
            1.4142135 = tf(freq=2.0), with freq of:
              2.0 = termFreq=2.0
            2.4695914 = idf(docFreq=10170, maxDocs=44218)
            0.0390625 = fieldNorm(doc=4186)
      0.03551324 = weight(_text_:22 in 4186) [ClassicSimilarity], result of:
        0.03551324 = score(doc=4186,freq=2.0), product of:
          0.18357785 = queryWeight, product of:
            3.5018296 = idf(docFreq=3622, maxDocs=44218)
            0.05242341 = 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)

Date: 22. 1.2011 12:51:07
Source: Journal of the American Society for Information Science and Technology. 62(2011) no.2, S.217-229

Marx, W.; Bornmann, L.: On the problems of dealing with bibliometric data (2014) 0.02

0.021307945 = product of:
  0.04261589 = sum of:
    0.04261589 = product of:
      0.08523178 = sum of:
        0.08523178 = weight(_text_:22 in 1239) [ClassicSimilarity], result of:
          0.08523178 = score(doc=1239,freq=2.0), product of:
            0.18357785 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.05242341 = queryNorm
            0.46428138 = fieldWeight in 1239, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.09375 = fieldNorm(doc=1239)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

Date: 18. 3.2014 19:13:22

Bornmann, L.; Mutz, R.: From P100 to P100' : a new citation-rank approach (2014) 0.01

0.0142052965 = product of:
  0.028410593 = sum of:
    0.028410593 = product of:
      0.056821186 = sum of:
        0.056821186 = weight(_text_:22 in 1431) [ClassicSimilarity], result of:
          0.056821186 = score(doc=1431,freq=2.0), product of:
            0.18357785 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.05242341 = queryNorm
            0.30952093 = fieldWeight in 1431, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0625 = fieldNorm(doc=1431)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

Date: 22. 8.2014 17:05:18

Bornmann, L.: How to analyze percentile citation impact data meaningfully in bibliometrics : the statistical analysis of distributions, percentile rank classes, and top-cited papers (2013) 0.01

0.010653973 = product of:
  0.021307945 = sum of:
    0.021307945 = product of:
      0.04261589 = sum of:
        0.04261589 = weight(_text_:22 in 656) [ClassicSimilarity], result of:
          0.04261589 = score(doc=656,freq=2.0), product of:
            0.18357785 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.05242341 = queryNorm
            0.23214069 = fieldWeight in 656, 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=656)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

Date: 22. 3.2013 19:44:17

Bornmann, L.: On the function of university rankings (2014) 0.01

0.010597459 = product of:
  0.021194918 = sum of:
    0.021194918 = product of:
      0.042389836 = sum of:
        0.042389836 = weight(_text_:2 in 1188) [ClassicSimilarity], result of:
          0.042389836 = score(doc=1188,freq=2.0), product of:
            0.1294644 = queryWeight, product of:
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.05242341 = queryNorm
            0.32742465 = fieldWeight in 1188, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.09375 = fieldNorm(doc=1188)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

Source: Journal of the Association for Information Science and Technology. 65(2014) no.2, S.428-429

Bornmann, L.: What is societal impact of research and how can it be assessed? : a literature survey (2013) 0.01

0.0052987295 = product of:
  0.010597459 = sum of:
    0.010597459 = product of:
      0.021194918 = sum of:
        0.021194918 = weight(_text_:2 in 606) [ClassicSimilarity], result of:
          0.021194918 = score(doc=606,freq=2.0), product of:
            0.1294644 = queryWeight, product of:
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.05242341 = queryNorm
            0.16371232 = fieldWeight in 606, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.046875 = fieldNorm(doc=606)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

Source: Journal of the American Society for Information Science and Technology. 64(2013) no.2, S.217-233

Bornmann, L.: Lässt sich die Qualität von Forschung messen? (2013) 0.01
```
0.0052987295 = product of:
  0.010597459 = sum of:
    0.010597459 = product of:
      0.021194918 = sum of:
        0.021194918 = weight(_text_:2 in 928) [ClassicSimilarity], result of:
          0.021194918 = score(doc=928,freq=2.0), product of:
            0.1294644 = queryWeight, product of:
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.05242341 = queryNorm
            0.16371232 = fieldWeight in 928, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.046875 = fieldNorm(doc=928)
      0.5 = coord(1/2)
  0.5 = coord(1/2)
```
Abstract

Grundsätzlich können wir bei Bewertungen in der Wissenschaft zwischen einer 'qualitative' Form, der Bewertung einer wissenschaftlichen Arbeit (z. B. eines Manuskripts oder Forschungsantrags) durch kompetente Peers, und einer 'quantitative' Form, der Bewertung von wissenschaftlicher Arbeit anhand bibliometrischer Indikatoren unterscheiden. Beide Formen der Bewertung sind nicht unumstritten. Die Kritiker des Peer Review sehen vor allem zwei Schwächen des Verfahrens: (1) Verschiedene Gutachter würden kaum in der Bewertung ein und derselben wissenschaftlichen Arbeit übereinstimmen. (2) Gutachterliche Empfehlungen würden systematische Urteilsverzerrungen aufweisen. Gegen die Verwendung von Zitierhäufigkeiten als Indikator für die Qualität einer wissenschaftlichen Arbeit wird seit Jahren eine Vielzahl von Bedenken geäußert. Zitierhäufigkeiten seien keine 'objektiven' Messungen von wissenschaftlicher Qualität, sondern ein kritisierbares Messkonstrukt. So wird unter anderem kritisiert, dass wissenschaftliche Qualität ein komplexes Phänomen darstelle, das nicht auf einer eindimensionalen Skala (d. h. anhand von Zitierhäufigkeiten) gemessen werden könne. Es werden empirische Ergebnisse zur Reliabilität und Fairness des Peer Review Verfahrens sowie Forschungsergebnisse zur Güte von Zitierhäufigkeiten als Indikator für wissenschaftliche Qualität vorgestellt.
Bornmann, L.; Daniel, H.-D.: Universality of citation distributions : a validation of Radicchi et al.'s relative indicator cf = c/c0 at the micro level using data from chemistry (2009) 0.00
```
0.004415608 = product of:
  0.008831216 = sum of:
    0.008831216 = product of:
      0.017662432 = sum of:
        0.017662432 = weight(_text_:2 in 2954) [ClassicSimilarity], result of:
          0.017662432 = score(doc=2954,freq=2.0), product of:
            0.1294644 = queryWeight, product of:
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.05242341 = queryNorm
            0.13642694 = fieldWeight in 2954, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.0390625 = fieldNorm(doc=2954)
      0.5 = coord(1/2)
  0.5 = coord(1/2)
```
Abstract

In a recently published PNAS paper, Radicchi, Fortunato, and Castellano (2008) propose the relative indicator cf as an unbiased indicator for citation performance across disciplines (fields, subject areas). To calculate cf, the citation rate for a single paper is divided by the average number of citations for all papers in the discipline in which the single paper has been categorized. cf values are said to lead to a universality of discipline-specific citation distributions. Using a comprehensive dataset of an evaluation study on Angewandte Chemie International Edition (AC-IE), we tested the advantage of using this indicator in practical application at the micro level, as compared with (1) simple citation rates, and (2) z-scores, which have been used in psychological testing for many years for normalization of test scores. To calculate z-scores, the mean number of citations of the papers within a discipline is subtracted from the citation rate of a single paper, and the difference is then divided by the citations' standard deviation for a discipline. Our results indicate that z-scores are better suited than cf values to produce universality of discipline-specific citation distributions.
Leydesdorff, L.; Bornmann, L.: Integrated impact indicators compared with impact factors : an alternative research design with policy implications (2011) 0.00
```
0.004415608 = product of:
  0.008831216 = sum of:
    0.008831216 = product of:
      0.017662432 = sum of:
        0.017662432 = weight(_text_:2 in 4919) [ClassicSimilarity], result of:
          0.017662432 = score(doc=4919,freq=2.0), product of:
            0.1294644 = queryWeight, product of:
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.05242341 = queryNorm
            0.13642694 = fieldWeight in 4919, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.0390625 = fieldNorm(doc=4919)
      0.5 = coord(1/2)
  0.5 = coord(1/2)
```
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.
Leydesdorff, L.; Zhou, P.; Bornmann, L.: How can journal impact factors be normalized across fields of science? : An assessment in terms of percentile ranks and fractional counts (2013) 0.00
```
0.004415608 = product of:
  0.008831216 = sum of:
    0.008831216 = product of:
      0.017662432 = sum of:
        0.017662432 = weight(_text_:2 in 532) [ClassicSimilarity], result of:
          0.017662432 = score(doc=532,freq=2.0), product of:
            0.1294644 = queryWeight, product of:
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.05242341 = queryNorm
            0.13642694 = fieldWeight in 532, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.0390625 = fieldNorm(doc=532)
      0.5 = coord(1/2)
  0.5 = coord(1/2)
```
Abstract

Using the CD-ROM version of the Science Citation Index 2010 (N = 3,705 journals), we study the (combined) effects of (a) fractional counting on the impact factor (IF) and (b) transformation of the skewed citation distributions into a distribution of 100 percentiles and six percentile rank classes (top-1%, top-5%, etc.). Do these approaches lead to field-normalized impact measures for journals? In addition to the 2-year IF (IF2), we consider the 5-year IF (IF5), the respective numerators of these IFs, and the number of Total Cites, counted both as integers and fractionally. These various indicators are tested against the hypothesis that the classification of journals into 11 broad fields by PatentBoard/NSF (National Science Foundation) provides statistically significant between-field effects. Using fractional counting the between-field variance is reduced by 91.7% in the case of IF5, and by 79.2% in the case of IF2. However, the differences in citation counts are not significantly affected by fractional counting. These results accord with previous studies, but the longer citation window of a fractionally counted IF5 can lead to significant improvement in the normalization across fields.
Bornmann, L.; Mutz, R.: Growth rates of modern science : a bibliometric analysis based on the number of publications and cited references (2015) 0.00
```
0.004415608 = product of:
  0.008831216 = sum of:
    0.008831216 = product of:
      0.017662432 = sum of:
        0.017662432 = weight(_text_:2 in 2261) [ClassicSimilarity], result of:
          0.017662432 = score(doc=2261,freq=2.0), product of:
            0.1294644 = queryWeight, product of:
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.05242341 = queryNorm
            0.13642694 = fieldWeight in 2261, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.0390625 = fieldNorm(doc=2261)
      0.5 = coord(1/2)
  0.5 = coord(1/2)
```
Abstract

Many studies (in information science) have looked at the growth of science. In this study, we reexamine the question of the growth of science. To do this we (a) use current data up to publication year 2012 and (b) analyze the data across all disciplines and also separately for the natural sciences and for the medical and health sciences. Furthermore, the data were analyzed with an advanced statistical technique-segmented regression analysis-which can identify specific segments with similar growth rates in the history of science. The study is based on two different sets of bibliometric data: (a) the number of publications held as source items in the Web of Science (WoS, Thomson Reuters) per publication year and (b) the number of cited references in the publications of the source items per cited reference year. We looked at the rate at which science has grown since the mid-1600s. In our analysis of cited references we identified three essential growth phases in the development of science, which each led to growth rates tripling in comparison with the previous phase: from less than 1% up to the middle of the 18th century, to 2 to 3% up to the period between the two world wars, and 8 to 9% to 2010.

Bornmann, L.; Ye, A.; Ye, F.: Identifying landmark publications in the long run using field-normalized citation data (2018) 0.00

0.004415608 = product of:
  0.008831216 = sum of:
    0.008831216 = product of:
      0.017662432 = sum of:
        0.017662432 = weight(_text_:2 in 4196) [ClassicSimilarity], result of:
          0.017662432 = score(doc=4196,freq=2.0), product of:
            0.1294644 = queryWeight, product of:
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.05242341 = queryNorm
            0.13642694 = fieldWeight in 4196, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.0390625 = fieldNorm(doc=4196)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

Source: Journal of documentation. 74(2018) no.2, S.278-288

Leydesdorff, L.; Bornmann, L.; Mingers, J.: Statistical significance and effect sizes of differences among research universities at the level of nations and worldwide based on the Leiden rankings (2019) 0.00
```
0.004415608 = product of:
  0.008831216 = sum of:
    0.008831216 = product of:
      0.017662432 = sum of:
        0.017662432 = weight(_text_:2 in 5225) [ClassicSimilarity], result of:
          0.017662432 = score(doc=5225,freq=2.0), product of:
            0.1294644 = queryWeight, product of:
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.05242341 = queryNorm
            0.13642694 = fieldWeight in 5225, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              2.4695914 = idf(docFreq=10170, maxDocs=44218)
              0.0390625 = fieldNorm(doc=5225)
      0.5 = coord(1/2)
  0.5 = coord(1/2)
```
Abstract

The Leiden Rankings can be used for grouping research universities by considering universities which are not statistically significantly different as homogeneous sets. The groups and intergroup relations can be analyzed and visualized using tools from network analysis. Using the so-called "excellence indicator" PPtop-10%-the proportion of the top-10% most-highly-cited papers assigned to a university-we pursue a classification using (a) overlapping stability intervals, (b) statistical-significance tests, and (c) effect sizes of differences among 902 universities in 54 countries; we focus on the UK, Germany, Brazil, and the USA as national examples. Although the groupings remain largely the same using different statistical significance levels or overlapping stability intervals, these classifications are uncorrelated with those based on effect sizes. Effect sizes for the differences between universities are small (w < .2). The more detailed analysis of universities at the country level suggests that distinctions beyond three or perhaps four groups of universities (high, middle, low) may not be meaningful. Given similar institutional incentives, isomorphism within each eco-system of universities should not be underestimated. Our results suggest that networks based on overlapping stability intervals can provide a first impression of the relevant groupings among universities. However, the clusters are not well-defined divisions between groups of universities.

Search (14 results, page 1 of 1)

Authors

Years

Languages

Themes