2010/07/27 by Loet Leydesdorff, Lutz Bornmann, Leydesdorff, Loet +1
Computer Science · Decision Sciences · #Data Analysis with R #Digital Libraries (cs.DL) #FOS: Computer and information sciences #FOS: Physical sciences #Physics and Society (physics.soc-ph) #Web visibility and informetrics #scientometrics and bibliometrics research
paper · pdf · doi:10.48550/arxiv.1007.4749
openalex publication_date 2010/07/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The ISI-Impact Factors suffer from a number of drawbacks, among them the statistics-why should one use the mean and not the median?-and the incomparability among fields of science because of systematic differences in citation behavior among fields. Can these drawbacks be counteracted by counting citation weights fractionally instead of using whole numbers in the numerators? (i) Fractional citation counts are normalized in terms of the citing sources and thus would take into account differences in citation behavior among fields of science. (ii) Differences in the resulting distributions can be tested statistically for their significance at different levels of aggregation. (iii) Fractional counting can be generalized to any document set including journals or groups of journals, and thus the significance of differences among both small and large sets can be tested. A list of fractionally counted Impact Factors for 2008 is available online at http://www.leydesdorff.net/weightedif/weightedif.xls. The in-between group variance among the thirteen fields of science identified in the U.S. Science and Engineering Indicators is not statistically significant after this normalization. Although citation behavior differs largely between disciplines, the reflection of these differences in fractionally counted citation distributions could not be used as a reliable instrument for the classification.