Search (17 results, page 1 of 1)

  • × author_ss:"Bornmann, L."
  1. Bornmann, L.; Moya Anegón, F.de: What proportion of excellent papers makes an institution one of the best worldwide? : Specifying thresholds for the interpretation of the results of the SCImago Institutions Ranking and the Leiden Ranking (2014) 0.02
    0.024729438 = product of:
      0.14837663 = sum of:
        0.14837663 = weight(_text_:ranking in 1235) [ClassicSimilarity], result of:
          0.14837663 = score(doc=1235,freq=12.0), product of:
            0.20271951 = queryWeight, product of:
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.03747799 = queryNorm
            0.7319307 = fieldWeight in 1235, product of:
              3.4641016 = tf(freq=12.0), with freq of:
                12.0 = termFreq=12.0
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.0390625 = fieldNorm(doc=1235)
      0.16666667 = coord(1/6)
    
    Abstract
    University rankings generally present users with the problem of placing the results given for an institution in context. Only a comparison with the performance of all other institutions makes it possible to say exactly where an institution stands. In order to interpret the results of the SCImago Institutions Ranking (based on Scopus data) and the Leiden Ranking (based on Web of Science data), in this study we offer thresholds with which it is possible to assess whether an institution belongs to the top 1%, top 5%, top 10%, top 25%, or top 50% of institutions in the world. The thresholds are based on the excellence rate or PPtop 10%. Both indicators measure the proportion of an institution's publications which belong to the 10% most frequently cited publications and are the most important indicators for measuring institutional impact. For example, while an institution must achieve a value of 24.63% in the Leiden Ranking 2013 to be considered one of the top 1% of institutions worldwide, the SCImago Institutions Ranking requires 30.2%.
  2. Bornmann, L.; Bauer, J.: Which of the world's institutions employ the most highly cited researchers : an analysis of the data from highlycited.com (2015) 0.02
    0.022844076 = product of:
      0.13706446 = sum of:
        0.13706446 = weight(_text_:ranking in 1556) [ClassicSimilarity], result of:
          0.13706446 = score(doc=1556,freq=4.0), product of:
            0.20271951 = queryWeight, product of:
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.03747799 = queryNorm
            0.67612857 = fieldWeight in 1556, product of:
              2.0 = tf(freq=4.0), with freq of:
                4.0 = termFreq=4.0
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.0625 = fieldNorm(doc=1556)
      0.16666667 = coord(1/6)
    
    Abstract
    In 2014, Thomson Reuters published a list of the most highly cited researchers worldwide (highlycited.com). Because the data are freely available for downloading and include the names of the researchers' institutions, we produced a ranking of the institutions on the basis of the number of highly cited researchers per institution. This ranking is intended to be a helpful amendment of other available institutional rankings.
  3. Bornmann, L.; Bauer, J.: Which of the world's institutions employ the most highly cited researchers : an analysis of the data from highlycited.com (2015) 0.02
    0.022844076 = product of:
      0.13706446 = sum of:
        0.13706446 = weight(_text_:ranking in 2223) [ClassicSimilarity], result of:
          0.13706446 = score(doc=2223,freq=4.0), product of:
            0.20271951 = queryWeight, product of:
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.03747799 = queryNorm
            0.67612857 = fieldWeight in 2223, product of:
              2.0 = tf(freq=4.0), with freq of:
                4.0 = termFreq=4.0
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.0625 = fieldNorm(doc=2223)
      0.16666667 = coord(1/6)
    
    Abstract
    In 2014, Thomson Reuters published a list of the most highly cited researchers worldwide (highlycited.com). Because the data are freely available for downloading and include the names of the researchers' institutions, we produced a ranking of the institutions on the basis of the number of highly cited researchers per institution. This ranking is intended to be a helpful amendment of other available institutional rankings.
  4. Bornmann, L.; Moya Anegón, F. de; Mutz, R.: Do universities or research institutions with a specific subject profile have an advantage or a disadvantage in institutional rankings? (2013) 0.02
    0.020983625 = product of:
      0.12590174 = sum of:
        0.12590174 = weight(_text_:ranking in 1109) [ClassicSimilarity], result of:
          0.12590174 = score(doc=1109,freq=6.0), product of:
            0.20271951 = queryWeight, product of:
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.03747799 = queryNorm
            0.62106377 = fieldWeight in 1109, product of:
              2.4494898 = tf(freq=6.0), with freq of:
                6.0 = termFreq=6.0
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.046875 = fieldNorm(doc=1109)
      0.16666667 = coord(1/6)
    
    Abstract
    Using data compiled for the SCImago Institutions Ranking, we look at whether the subject area type an institution (university or research-focused institution) belongs to (in terms of the fields researched) has an influence on its ranking position. We used latent class analysis to categorize institutions based on their publications in certain subject areas. Even though this categorization does not relate directly to scientific performance, our results show that it exercises an important influence on the outcome of a performance measurement: Certain subject area types of institutions have an advantage in the ranking positions when compared with others. This advantage manifests itself not only when performance is measured with an indicator that is not field-normalized but also for indicators that are field-normalized.
  5. Dobrota, M.; Bulajic, M.; Bornmann, L.; Jeremic, V.: ¬A new approach to the QS university ranking using the composite I-distance indicator : uncertainty and sensitivity analyses (2016) 0.02
    0.020983625 = product of:
      0.12590174 = sum of:
        0.12590174 = weight(_text_:ranking in 2500) [ClassicSimilarity], result of:
          0.12590174 = score(doc=2500,freq=6.0), product of:
            0.20271951 = queryWeight, product of:
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.03747799 = queryNorm
            0.62106377 = fieldWeight in 2500, product of:
              2.4494898 = tf(freq=6.0), with freq of:
                6.0 = termFreq=6.0
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.046875 = fieldNorm(doc=2500)
      0.16666667 = coord(1/6)
    
    Abstract
    Some major concerns of universities are to provide quality in higher education and enhance global competitiveness, thus ensuring a high global rank and an excellent performance evaluation. This article examines the Quacquarelli Symonds (QS) World University Ranking methodology, pointing to a drawback of using subjective, possibly biased, weightings to build a composite indicator (QS scores). We propose an alternative approach to creating QS scores, which is referred to as the composite I-distance indicator (CIDI) methodology. The main contribution is the proposal of a composite indicator weights correction based on the CIDI methodology. It leads to the improved stability and reduced uncertainty of the QS ranking system. The CIDI methodology is also applicable to other university rankings by proposing a specific statistical approach to creating a composite indicator.
  6. Bornmann, L.: How well does a university perform in comparison with its peers? : The use of odds, and odds ratios, for the comparison of institutional citation impact using the Leiden Rankings (2015) 0.02
    0.019988567 = product of:
      0.1199314 = sum of:
        0.1199314 = weight(_text_:ranking in 2340) [ClassicSimilarity], result of:
          0.1199314 = score(doc=2340,freq=4.0), product of:
            0.20271951 = queryWeight, product of:
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.03747799 = queryNorm
            0.5916125 = fieldWeight in 2340, product of:
              2.0 = tf(freq=4.0), with freq of:
                4.0 = termFreq=4.0
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.0546875 = fieldNorm(doc=2340)
      0.16666667 = coord(1/6)
    
    Abstract
    This study presents the calculation of odds, and odds ratios, for the comparison of the citation impact of universities in the Leiden Ranking. Odds and odds ratios can be used to measure the performance difference between a selected university and competing institutions, or the average of selected competitors, in a relatively simple but clear way.
    Object
    Leiden Ranking
  7. Bornmann, L.; Mutz, R.; Daniel, H.-D.: Multilevel-statistical reformulation of citation-based university rankings : the Leiden ranking 2011/2012 (2013) 0.02
    0.017486354 = product of:
      0.10491812 = sum of:
        0.10491812 = weight(_text_:ranking in 1007) [ClassicSimilarity], result of:
          0.10491812 = score(doc=1007,freq=6.0), product of:
            0.20271951 = queryWeight, product of:
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.03747799 = queryNorm
            0.51755315 = fieldWeight in 1007, product of:
              2.4494898 = tf(freq=6.0), with freq of:
                6.0 = termFreq=6.0
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.0390625 = fieldNorm(doc=1007)
      0.16666667 = coord(1/6)
    
    Abstract
    Since the 1990s, with the heightened competition and the strong growth of the international higher education market, an increasing number of rankings have been created that measure the scientific performance of an institution based on data. The Leiden Ranking 2011/2012 (LR) was published early in 2012. Starting from Goldstein and Spiegelhalter's (1996) recommendations for conducting quantitative comparisons among institutions, in this study we undertook a reformulation of the LR by means of multilevel regression models. First, with our models we replicated the ranking results; second, the reanalysis of the LR data showed that only 5% of the PPtop10% total variation is attributable to differences between universities. Beyond that, about 80% of the variation between universities can be explained by differences among countries. If covariates are included in the model the differences among most of the universities become meaningless. Our findings have implications for conducting university rankings in general and for the LR in particular. For example, with Goldstein-adjusted confidence intervals, it is possible to interpret the significance of differences among universities meaningfully: Rank differences among universities should be interpreted as meaningful only if their confidence intervals do not overlap.
  8. Bornmann, L.: How much does the expected number of citations for a publication change if it contains the address of a specific scientific institute? : a new approach for the analysis of citation data on the institutional level based on regression models (2016) 0.01
    0.010095751 = product of:
      0.0605745 = sum of:
        0.0605745 = weight(_text_:ranking in 3095) [ClassicSimilarity], result of:
          0.0605745 = score(doc=3095,freq=2.0), product of:
            0.20271951 = queryWeight, product of:
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.03747799 = queryNorm
            0.29880944 = fieldWeight in 3095, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.0390625 = fieldNorm(doc=3095)
      0.16666667 = coord(1/6)
    
    Abstract
    Citation data for institutes are generally provided as numbers of citations or as relative citation rates (as, for example, in the Leiden Ranking). These numbers can then be compared between the institutes. This study aims to present a new approach for the evaluation of citation data at the institutional level, based on regression models. As example data, the study includes all articles and reviews from the Web of Science for the publication year 2003 (n?=?886,416 papers). The study is based on an in-house database of the Max Planck Society. The study investigates how much the expected number of citations for a publication changes if it contains the address of an institute. The calculation of the expected values allows, on the one hand, investigating how the citation impact of the papers of an institute appears in comparison with the total of all papers. On the other hand, the expected values for several institutes can be compared with one another or with a set of randomly selected publications. Besides the institutes, the regression models include factors which can be assumed to have a general influence on citation counts (e.g., the number of authors).
  9. Bauer, J.; Leydesdorff, L.; Bornmann, L.: Highly cited papers in Library and Information Science (LIS) : authors, institutions, and network structures (2016) 0.01
    0.010095751 = product of:
      0.0605745 = sum of:
        0.0605745 = weight(_text_:ranking in 3231) [ClassicSimilarity], result of:
          0.0605745 = score(doc=3231,freq=2.0), product of:
            0.20271951 = queryWeight, product of:
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.03747799 = queryNorm
            0.29880944 = fieldWeight in 3231, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              5.4090285 = idf(docFreq=537, maxDocs=44218)
              0.0390625 = fieldNorm(doc=3231)
      0.16666667 = coord(1/6)
    
    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.
  10. Bornmann, L.: On the function of university rankings (2014) 0.00
    0.0034158952 = product of:
      0.02049537 = sum of:
        0.02049537 = product of:
          0.06148611 = sum of:
            0.06148611 = weight(_text_:29 in 1188) [ClassicSimilarity], result of:
              0.06148611 = score(doc=1188,freq=2.0), product of:
                0.13183585 = queryWeight, product of:
                  3.5176873 = idf(docFreq=3565, maxDocs=44218)
                  0.03747799 = queryNorm
                0.46638384 = fieldWeight in 1188, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.5176873 = idf(docFreq=3565, maxDocs=44218)
                  0.09375 = fieldNorm(doc=1188)
          0.33333334 = coord(1/3)
      0.16666667 = coord(1/6)
    
    Date
    29. 1.2014 16:55:03
  11. Marx, W.; Bornmann, L.: On the problems of dealing with bibliometric data (2014) 0.00
    0.0033851666 = product of:
      0.020311 = sum of:
        0.020311 = product of:
          0.060932998 = sum of:
            0.060932998 = weight(_text_:22 in 1239) [ClassicSimilarity], result of:
              0.060932998 = score(doc=1239,freq=2.0), product of:
                0.13124153 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.03747799 = 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)
          0.33333334 = coord(1/3)
      0.16666667 = coord(1/6)
    
    Date
    18. 3.2014 19:13:22
  12. Bornmann, L.; Mutz, R.: From P100 to P100' : a new citation-rank approach (2014) 0.00
    0.0022567778 = product of:
      0.013540667 = sum of:
        0.013540667 = product of:
          0.040622 = sum of:
            0.040622 = weight(_text_:22 in 1431) [ClassicSimilarity], result of:
              0.040622 = score(doc=1431,freq=2.0), product of:
                0.13124153 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.03747799 = 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)
          0.33333334 = coord(1/3)
      0.16666667 = coord(1/6)
    
    Date
    22. 8.2014 17:05:18
  13. Bornmann, L.; Marx, W.: Distributions instead of single numbers : percentiles and beam plots for the assessment of single researchers (2014) 0.00
    0.0019926056 = product of:
      0.011955633 = sum of:
        0.011955633 = product of:
          0.035866898 = sum of:
            0.035866898 = weight(_text_:29 in 1190) [ClassicSimilarity], result of:
              0.035866898 = score(doc=1190,freq=2.0), product of:
                0.13183585 = queryWeight, product of:
                  3.5176873 = idf(docFreq=3565, maxDocs=44218)
                  0.03747799 = queryNorm
                0.27205724 = fieldWeight in 1190, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.5176873 = idf(docFreq=3565, maxDocs=44218)
                  0.0546875 = fieldNorm(doc=1190)
          0.33333334 = coord(1/3)
      0.16666667 = coord(1/6)
    
    Date
    29. 1.2014 15:58:21
  14. 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) 0.00
    0.0016925833 = product of:
      0.0101555 = sum of:
        0.0101555 = product of:
          0.030466499 = sum of:
            0.030466499 = weight(_text_:22 in 656) [ClassicSimilarity], result of:
              0.030466499 = score(doc=656,freq=2.0), product of:
                0.13124153 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.03747799 = 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)
          0.33333334 = coord(1/3)
      0.16666667 = coord(1/6)
    
    Date
    22. 3.2013 19:44:17
  15. Leydesdorff, L.; Bornmann, L.; Wagner, C.S.: ¬The relative influences of government funding and international collaboration on citation impact (2019) 0.00
    0.0016925833 = product of:
      0.0101555 = sum of:
        0.0101555 = product of:
          0.030466499 = sum of:
            0.030466499 = weight(_text_:22 in 4681) [ClassicSimilarity], result of:
              0.030466499 = score(doc=4681,freq=2.0), product of:
                0.13124153 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.03747799 = 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)
          0.33333334 = coord(1/3)
      0.16666667 = coord(1/6)
    
    Date
    8. 1.2019 18:22:45
  16. Bornmann, L.; Schier, H.; Marx, W.; Daniel, H.-D.: Is interactive open access publishing able to identify high-impact submissions? : a study on the predictive validity of Atmospheric Chemistry and Physics by using percentile rank classes (2011) 0.00
    0.0014232898 = product of:
      0.008539738 = sum of:
        0.008539738 = product of:
          0.025619213 = sum of:
            0.025619213 = weight(_text_:29 in 4132) [ClassicSimilarity], result of:
              0.025619213 = score(doc=4132,freq=2.0), product of:
                0.13183585 = queryWeight, product of:
                  3.5176873 = idf(docFreq=3565, maxDocs=44218)
                  0.03747799 = queryNorm
                0.19432661 = fieldWeight in 4132, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.5176873 = idf(docFreq=3565, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=4132)
          0.33333334 = coord(1/3)
      0.16666667 = coord(1/6)
    
    Date
    8. 1.2011 18:29:40
  17. 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
    0.0014104862 = product of:
      0.008462917 = sum of:
        0.008462917 = product of:
          0.025388751 = sum of:
            0.025388751 = weight(_text_:22 in 4186) [ClassicSimilarity], result of:
              0.025388751 = score(doc=4186,freq=2.0), product of:
                0.13124153 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.03747799 = 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)
          0.33333334 = coord(1/3)
      0.16666667 = coord(1/6)
    
    Date
    22. 1.2011 12:51:07