, Volume 84, Issue 2, pp 465–479 | Cite as

The stability of the h-index

  • Monika Henzinger
  • Jacob Suñol
  • Ingmar WeberEmail author


Over the last years the h-index has gained popularity as a measure for comparing the impact of scientists. We investigate if ranking according to the h-index is stable with respect to (i) different choices of citation databases, (ii) normalizing citation counts by the number of authors or by removing self-citations, (iii) small amounts of noise created by randomly removing citations or publications and (iv) small changes in the definition of the index. In experiments for 5,283 computer scientists and 1,354 physicists we show that although the ranking of the h-index is stable under most of these changes, it is unstable when different databases are used. Therefore, comparisons based on the h-index should only be trusted when the rankings of multiple citation databases agree.


h-index Ranking scientists Stability analysis Citation databases 


  1. Ball, P. (2007). Achievement index climbs the ranks. Nature, 448(7155), 737.CrossRefGoogle Scholar
  2. Bornmann, L., & Daniel, H. (2005). Does the h-index for ranking of scientists really work? Scientometrics, 65(3), 391–392.CrossRefGoogle Scholar
  3. Bornmann, L., & Daniel, H. D. (2009). The state of h index research. Is the h index the ideal way to measure research performance? EMBO reports, 10(1), 2–6.CrossRefGoogle Scholar
  4. Hirsch, J. (2005). An index to quantify an individual’s scientific research output. Proceedings of the National Academy of Sciences, 102(46), 16569–16572.CrossRefGoogle Scholar
  5. Hirsch, J. (2007). Does the h index have predictive power? Proceedings of the National Academy of Sciences, 104(49), 19193.CrossRefGoogle Scholar
  6. Kelly, C., & Jennions, M. (2006). The h index and career assessment by numbers. Trends in Ecology & Evolution, 21(4), 167–170.CrossRefGoogle Scholar
  7. Kelly, C., & Jennions, M. (2007). H-index: age and sex make it unreliable. Nature, 449(7161), 403.CrossRefGoogle Scholar
  8. Kurien, B. (2008). Name variations can hit citation rankings. Nature, 453(7194), 450.CrossRefGoogle Scholar
  9. Schreiber, M. (2007). Self-citation corrections for the Hirsch index. Europhysics Letters, 78(3), 0295–5075.CrossRefGoogle Scholar
  10. van Raan, A. (2006). Comparison of the Hirsch-index with standard bibliometric indicators and with peer judgment for 147 chemistry research groups. Scientometrics, 67(3), 491–502.Google Scholar
  11. Vanclay, J. K. (2007). On the robustness of the h-index. Journal of the American Society for Information Science and Technology, 58, 1547–1550.CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2009

Authors and Affiliations

  1. 1.Ecole Polytechnique Fédérale de LausanneLausanneSwitzerland

Personalised recommendations