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  • × author_ss:"Bornmann, L."
  1. Marx, W.; Bornmann, L.: On the problems of dealing with bibliometric data (2014) 0.01 
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    Date
    18. 3.2014 19:13:22
  2. Bornmann, L.; Daniel, H.-D.: What do we know about the h index? (2007) 0.01 
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    Abstract
    Jorge Hirsch recently proposed the h index to quantify the research output of individual scientists. The new index has attracted a lot of attention in the scientific community. The claim that the h index in a single number provides a good representation of the scientific lifetime achievement of a scientist as well as the (supposed) simple calculation of the h index using common literature databases lead to the danger of improper use of the index. We describe the advantages and disadvantages of the h index and summarize the studies on the convergent validity of this index. We also introduce corrections and complements as well as single-number alternatives to the h index.
    Object
    H-Index
  3. Leydesdorff, L.; Bornmann, L.; Mutz, R.; Opthof, T.: Turning the tables on citation analysis one more time : principles for comparing sets of documents (2011) 0.01 
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    Abstract
    We submit newly developed citation impact indicators based not on arithmetic averages of citations but on percentile ranks. Citation distributions are-as a rule-highly skewed and should not be arithmetically averaged. With percentile ranks, the citation score of each paper is rated in terms of its percentile in the citation distribution. The percentile ranks approach allows for the formulation of a more abstract indicator scheme that can be used to organize and/or schematize different impact indicators according to three degrees of freedom: the selection of the reference sets, the evaluation criteria, and the choice of whether or not to define the publication sets as independent. Bibliometric data of seven principal investigators (PIs) of the Academic Medical Center of the University of Amsterdam are used as an exemplary dataset. We demonstrate that the proposed family indicators [R(6), R(100), R(6, k), R(100, k)] are an improvement on averages-based indicators because one can account for the shape of the distributions of citations over papers.
  4. Bornmann, L.; Mutz, R.: From P100 to P100' : a new citation-rank approach (2014) 0.01 
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    Date
    22. 8.2014 17:05:18
  5. Collins, H.; Bornmann, L.: On scientific misconduct (2014) 0.01 
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  6. 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 
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    Date
    22. 3.2013 19:44:17
  7. Leydesdorff, L.; Bornmann, L.; Wagner, C.S.: ¬The relative influences of government funding and international collaboration on citation impact (2019) 0.01 
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    Date
    8. 1.2019 18:22:45
  8. Bornmann, L.; Mutz, R.; Daniel, H.-D.: Are there better indices for evaluation purposes than the h index? : a comparison of nine different variants of the h index using data from biomedicine (2008) 0.01 
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    Abstract
    In this study, we examined empirical results on the h index and its most important variants in order to determine whether the variants developed are associated with an incremental contribution for evaluation purposes. The results of a factor analysis using bibliographic data on postdoctoral researchers in biomedicine indicate that regarding the h index and its variants, we are dealing with two types of indices that load on one factor each. One type describes the most productive core of a scientist's output and gives the number of papers in that core. The other type of indices describes the impact of the papers in the core. Because an index for evaluative purposes is a useful yardstick for comparison among scientists if the index corresponds strongly with peer assessments, we calculated a logistic regression analysis with the two factors resulting from the factor analysis as independent variables and peer assessment of the postdoctoral researchers as the dependent variable. The results of the regression analysis show that peer assessments can be predicted better using the factor impact of the productive core than using the factor quantity of the productive core.
  9. Bornmann, L.; Mutz, R.; Daniel, H.D.: Do we need the h index and its variants in addition to standard bibliometric measures? (2009) 0.01 
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    Abstract
    In this study, we investigate whether there is a need for the h index and its variants in addition to standard bibliometric measures (SBMs). Results from our recent study (L. Bornmann, R. Mutz, & H.-D. Daniel, 2008) have indicated that there are two types of indices: One type of indices (e.g., h index) describes the most productive core of a scientist's output and informs about the number of papers in the core. The other type of indices (e.g., a index) depicts the impact of the papers in the core. In evaluative bibliometric studies, the two dimensions quantity and quality of output are usually assessed using the SBMs number of publications (for the quantity dimension) and total citation counts (for the impact dimension). We additionally included the SBMs into the factor analysis. The results of the newly calculated analysis indicate that there is a high intercorrelation between number of publications and the indices that load substantially on the factor Quantity of the Productive Core as well as between total citation counts and the indices that load substantially on the factor Impact of the Productive Core. The high-loading indices and SBMs within one performance dimension could be called redundant in empirical application, as high intercorrelations between different indicators are a sign for measuring something similar (or the same). Based on our findings, we propose the use of any pair of indicators (one relating to the number of papers in a researcher's productive core and one relating to the impact of these core papers) as a meaningful approach for comparing scientists.
    Object
    h-Index
  10. 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) 0.01 
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    Date
    22. 1.2011 12:51:07
  11. 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 
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  12. Bornmann, L.: Lässt sich die Qualität von Forschung messen? (2013) 0.00 
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    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.
  13. Bornmann, L.; Daniel, H.-D.: Multiple publication on a single research study: does it pay? : The influence of number of research articles on total citation counts in biomedicine (2007) 0.00 
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  14. 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 
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  15. Marx, W.; Bornmann, L.; Cardona, M.: Reference standards and reference multipliers for the comparison of the citation impact of papers published in different time periods (2010) 0.00 
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    Abstract
    In this study, reference standards and reference multipliers are suggested as a means to compare the citation impact of earlier research publications in physics (from the period of "Little Science" in the early 20th century) with that of contemporary papers (from the period of "Big Science," beginning around 1960). For the development of time-specific reference standards, the authors determined (a) the mean citation rates of papers in selected physics journals as well as (b) the mean citation rates of all papers in physics published in 1900 (Little Science) and in 2000 (Big Science); this was accomplished by relying on the processes of field-specific standardization in bibliometry. For the sake of developing reference multipliers with which the citation impact of earlier papers can be adjusted to the citation impact of contemporary papers, they combined the reference standards calculated for 1900 and 2000 into their ratio. The use of reference multipliers is demonstrated by means of two examples involving the time adjusted h index values for Max Planck and Albert Einstein.
  16. Bornmann, L.; Mutz, R.; Daniel, H.-D.: Multilevel-statistical reformulation of citation-based university rankings : the Leiden ranking 2011/2012 (2013) 0.00 
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  17. Mutz, R.; Bornmann, L.; Daniel, H.-D.: Testing for the fairness and predictive validity of research funding decisions : a multilevel multiple imputation for missing data approach using ex-ante and ex-post peer evaluation data from the Austrian science fund (2015) 0.00 
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  18. Bornmann, L.; Thor, A.; Marx, W.; Schier, H.: ¬The application of bibliometrics to research evaluation in the humanities and social sciences : an exploratory study using normalized Google Scholar data for the publications of a research institute (2016) 0.00 
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  19. Bornmann, L.; Daniel, H.-D.: Selecting manuscripts for a high-impact journal through peer review : a citation analysis of communications that were accepted by Angewandte Chemie International Edition, or rejected but published elsewhere (2008) 0.00 
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