, Volume 101, Issue 3, pp 1781–1787 | Cite as

Single parameter indices and bibliometric outliers

  • Gangan Prathap


In this paper, we look at the issue of the high-end of research performance which is captured in the tail of a citation distribution. As the mean is insufficient to capture the skewness of such distributions, a consistency or concentration measure is the additional parameter needed. We show that the h-index is only approximately a heuristic mock of a composite indicator built from three primary indicators which are the number, mean and consistency term. The z-index is able to sense the change in consistency in the distribution due to the outliers in the tail of the distribution.


Scientometric distributions Extreme values Mean Quantity Consistency Citation h-Index z-Index 


  1. De Visscher, A. (2011). What does the g-index really measure? Journal of the American Society for Information Science and Technology, 62(11), 2290–2293.CrossRefGoogle Scholar
  2. Garfield, E. (1955). Citation indexes to science: A new dimension in documentation through association of ideas. Science, 122(3159), 108–111.CrossRefGoogle Scholar
  3. Garfield, E. (1999). Journal impact factor: A brief review. Canadian Medical Association Journal, 161(8), 979–980.Google Scholar
  4. Garfield, E. (2005). The agony and the ecstasy: The history and meaning of the journal impact factor. In International Congress on Peer Review and Biomedical Publication. Retrieved Oct 15, 2013 from
  5. Glänzel, W. (2009). The multi-dimensionality of journal impact. Scientometrics, 78(2), 355–374.CrossRefGoogle Scholar
  6. Glänzel, W. (2013a). High-end performance or outlier? Evaluating the tail of scientometric distribution. Scientometrics, 97(1), 13–23.CrossRefGoogle Scholar
  7. Glänzel, W. (2013b). The application of citation-based performance classes in disciplinary and multidisciplinary assessment. In J. Gorraiz, E. Schiebel, Ch. Gumpenberger, M. Hörlesberger, & H. F. Moed (Eds.), Proceedings of ISSI 2013The 14th International Conference on Scientometrics and Informetrics, Vienna, Austria (Vol. I, pp. 109–122).Google Scholar
  8. Glanzel, W., & Moed, H. F. (2013). Opinion paper: thoughts and facts on bibliometric indicators. Scientometrics, 96(1), 381–394.CrossRefGoogle Scholar
  9. Glänzel, W., Thijs, B., Debackere, K. (2013). The application of citation-based performance classes in institutional research assessment. In S. Hinze, A. Lottmann (Eds.), Translational Twists and Turns: Science as a Socio-Economic Endeavour, Proceedings of STI 2013 Berlin (18th International Conference on Science and Technology Indicators) (pp. 122–129).Google Scholar
  10. Hirsch, J.E. (2005). An index to quantify an individual’s scientific research output. In Proceedings of the National Academy of Sciences of the United States of America (Vol. 102, no. 46, pp. 16569–16572).Google Scholar
  11. Pendlebury, D. A., & Adams, J. (2012). Comments on a critique of the Thomson Reuters journal impact factor. Scientometrics, 92(2), 395–401.CrossRefGoogle Scholar
  12. Prathap, G. (2010a). Is there a place for a mock h-index? Scientometrics, 84, 153–165.CrossRefGoogle Scholar
  13. Prathap, G. (2010b). The 100 most prolific economists using the p-index. Scientometrics, 84, 167–172.CrossRefGoogle Scholar
  14. Prathap, G. (2011a). The energy–exergy–entropy (or EEE) sequences in bibliometric assessment. Scientometrics, 87, 515–524.CrossRefGoogle Scholar
  15. Prathap, G. (2011b). Quasity, when quantity has a quality all of its own—Toward a theory of performance. Scientometrics, 88, 555–562.CrossRefGoogle Scholar
  16. Prathap, G. (2013a). The Zynergy-index and the formula for the h-index. Journal of the American Society for Information Science and Technology. doi: 10.1002/asi.23046.MATHGoogle Scholar
  17. Prathap, G. (2013b). Quantity, quality, and consistency as bibliometric indicators. Journal of the American Society for Information Science and Technology. doi: 10.1002/asi.23008.MATHGoogle Scholar
  18. Prathap, G. (2013c). Measures for impact, consistency, and the h- and g-indices. Journal of the American Society for Information Science and Technology. doi: 10.1002/asi.23028.MATHGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2013

Authors and Affiliations

  1. 1.CSIR National Institute for Interdisciplinary Science and TechnologyThiruvananthapuramIndia

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