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hIa: an individual annual h-index to accommodate disciplinary and career length differences

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Hirsch’s h-index cannot be used to compare academics that work in different disciplines or are at different career stages. Therefore, a metric that corrects for these differences would provide information that the h-index and its many current refinements cannot deliver. This article introduces such a metric, namely the hI,annual (or hIa for short). The hIa-index represents the average annual increase in the individual h-index. Using a sample of 146 academics working in five major disciplines and representing a wide variety of career lengths, we demonstrate that this metric attenuates h-index differences attributable to disciplinary background and career length. It is also easy to calculate with readily available data from all major bibliometric databases, such as Thomson Reuters Web of Knowledge, Scopus and Google Scholar. Finally, as the metric represents the average number of single-author-equivalent “impactful” articles that an academic has published per year, it also allows an intuitive interpretation. Although just like any other metric, the hIa-index should never be used as the sole criterion to evaluate academics, we argue that it provides a more reliable comparison between academics than currently available metrics.

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  1. Academic age could be adjusted if a first publication occurred years before a steady stream of research output materialised, as might the case for a published conference paper or a book review.

  2. We also collected data for Google Scholar and the Web of Science (ISI); the results for these databases were very similar in terms of the hIa-index’s attenuation of differences between disciplines and career length. The average hIa-index was very similar in Scopus and ISI, but was approximately 30–35 % higher in Google Scholar.

  3. Two professors in Law and Physics had to be removed from the final sample as their publication patterns were very uncharacteristic of their field.

  4. For instance, Veterinary Sciences, Land and Environment, and Earth Sciences could have been classified into a separate major discipline of Environmental Sciences. However, their h, hIA and author per paper metrics were very similar to the Sciences; hence they were merged into the Sciences category. Architecture, Building and Planning displays similarities with Engineering, the Social Sciences and the Humanities. However, our selected academics were all in the Architecture/Design field, which is more aligned with the Humanities tradition; hence they were classified into the Humanities cluster.

  5. Apart from sample idiosyncrasies, this may have been caused by three factors. First, academics in the (Life) Sciences normally start publishing during their PhD, whereas this is less common for academics in other disciplines. Second, academics in the (Life) Sciences often have a longer career trajectory, with most academics taking on one or more postdocs before appointment as assistant professor. Finally, in Engineering, the Social Sciences and Humanities, academics might well have early career publications in outlets not included in Scopus, such as books or conference proceedings, or in journals not currently included in Scopus.


  • Adler, N., & Harzing, A. W. (2009). When knowledge wins: Transcending the sense and nonsense of academic rankings. The Academy of Management Learning & Education, 8(1), 72–95.

    Article  Google Scholar 

  • Antonakis, J., & Lalive, R. (2008). Quantifying scholarly impact: IQp versus the Hirsch h. Journal of the American Society for Information Science and Technology, 59(6), 956–969.

    Article  Google Scholar 

  • Batista, P. D., Campiteli, M. G., & Kinouchi, O. (2006). Is it possible to compare researchers with different scientific interests? Scientometrics, 68(1), 179–189.

    Article  Google Scholar 

  • Börner, K., Dall’Asta, L., Ke, W., & Vespignani, A. (2005). Studying the emerging global brain: Analyzing and visualizing the impact of co-authorship teams. Complexity, 10(4), 57–67.

    Article  Google Scholar 

  • Bornmann, L., & Marx, W. (2011). The h index as a research performance indicator. European Science Editing, 37(3), 77–80.

    Google Scholar 

  • Bornmann, L., Mutz, R., Hug, S. E., & Daniel, H. D. (2011). A multilevel meta-analysis of studies reporting correlations between the h-index and 37 different h-index variants. Journal of Informetrics, 5(3), 346–359.

    Article  Google Scholar 

  • Bourke, P. (1997). Discipline boundaries in the social sciences. Occasional Paper Series 1. Canberra: Academy of the Social Sciences.

  • Burrell, Q. L. (2007). Hirsch index or Hirsch rate? Some thoughts arising from Liang’s data. Scientometrics, 73(1), 19–28.

    Article  Google Scholar 

  • Egghe, L. (2006). Theory and practise of the g-index. Scientometrics, 69(1), 131–152.

    Article  MathSciNet  Google Scholar 

  • Glänzel, W., & Thijs, B. (2004). Does co-authorship inflate the share of self-citations? Scientometrics, 61(3), 395–404.

    Article  Google Scholar 

  • Hagen, N. T. (2009). Credit for coauthors. Science, 323(5914), 583.

    Article  Google Scholar 

  • Hare, J. (2012, December 6). How universities performed in ERA 2012. The Australian. Retrieved from

  • Harzing, A. W. (2007) Publish or Perish. Retrieved from

  • Harzing, A. W. (2010). The Publish or Perish book: Your guide to effective and responsible citation analysis. Melbourne: Tarma Software Research.

    Google Scholar 

  • Hellqvist, B. (2010). Referencing in the humanities and its implications for citation analysis. Journal of the American Society for Information Science and Technology, 61(2), 310–318.

    Google Scholar 

  • Hirsch, J. E. (2005). An index to quantify an individual’s scientific research output. Proceedings of the National Academy of Sciences of the United States of America, 102(46), 16569–16572.

    Article  Google Scholar 

  • Hirsch, J. E. (2010). An index to quantify an individual’s scientific research output that takes into account the effect of multiple coauthorship. Scientometrics, 85(3), 741–754.

    Article  Google Scholar 

  • Katz, J. S., & Martin, B. R. (1997). What is research collaboration? Research Policy, 26(1), 1–18.

    Article  Google Scholar 

  • Kaur, J., Hoang, D. T., Sun, X., Possamai, L., JafariAsbagh, M., Patil, S., et al. (2012). Scholarometer: A social framework for analyzing impact across disciplines. PLoS One, 7(9), e43235.

    Article  Google Scholar 

  • Kaur, J., Radicchi, F., & Menczer, F. (2013). Universality of scholarly impact metrics. Journal of Informetrics, 7(4), 924–932.

    Article  Google Scholar 

  • Larivière, V., Gingras, Y., & Archambault, É. (2006). Canadian collaboration networks: A comparative analysis of the natural sciences, social sciences and the humanities. Scientometrics, 68(3), 519–533.

    Article  Google Scholar 

  • Marginson, S. (2007). Global university rankings: Implications in general and for Australia. Journal of Higher Education Policy and Management, 29(2), 131–142.

    Article  Google Scholar 

  • Nederhof, A. J. (2006). Bibliometric monitoring of research performance in the social sciences and the humanities: A review. Scientometrics, 66(1), 81–100.

    Article  MathSciNet  Google Scholar 

  • Schreiber, M. (2008). A modification of the h-index: The hm-index accounts for multi-authored manuscripts. Journal of Informetrics, 2(3), 211–216.

    Article  MathSciNet  Google Scholar 

  • Tol, R. S. (2011). Credit where credit’s due: accounting for co-authorship in citation counts. Scientometrics, 89(1), 291–299.

    Article  Google Scholar 

  • Zuckerman, H., & Merton, R. K. (1971). Patterns of evaluation in science: Institutionalisation, structure and functions of the referee system. Minerva, 9(1), 66–100.

    Article  Google Scholar 

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Correspondence to Anne-Wil Harzing.

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Harzing, AW., Alakangas, S. & Adams, D. hIa: an individual annual h-index to accommodate disciplinary and career length differences. Scientometrics 99, 811–821 (2014).

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