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Bibliometrics - Impact Factor, H-index, and More: h-index

Provides links to resources for bibliometric analysis, including journal ranking indices, such as impact factor, and author impact measures, such as h-index.

What is h-index?


The leading factor for determining an author’s impact of published work has become the h-index.  The  h-index was developed by J.E. Hirsch from the University of California at San Diego in 2005 (Hirsch 2005).  He argues that previous metrics, such as total number of papers, total number of citations, and citations per paper, were not sufficient to fairly measure the impact of an author.  Hence, Hirsch proposed the h-index, which looks at all the publications and orders them by the number of citations (largest to smallest).  The h is the number of publications that have at least h citations.  


In the table below, the articles are listed in order of citation and the h-index is 93 (highlighted section) because at least 93 articles have been cited 93 times.

In this example the document number and citation number are the same, which may not always be the case.  If document 93 had 92 citations, then the h-index would be 92 because the h-index (h) is when the number of publications (N) has at least h citations or more.


Or you can chart the number of documents compared to their citations and see where they intersect with document #=citation.

How to find your h-index?

How do you determine your h-index?

There are a few ways to determine your h-index.  However, depending on the method, you will get a different number, so always remember to cite where you found your h-index.  The three major locations for an h-index is Google Scholar, Web of Science, and Scopus.  To understand better the different platforms, check out Michigan State’s LibGuide.

The h-index of an author will be different depending on which search engine was used.  This is mainly due to how the database discovers articles and how it counts citations. 


On Scopus, you can search by author and find a researcher’s profile.  The number of documents and citations, as well as their h-index is displayed on their profile.


Web of Science

On Web of Science, similarly, by clicking on the author profile, the number of publications and citations, as well as h-index can be viewed. 

Google Scholar

To access your metrics first create a google scholar account using your CSHL email address.  Go to Google Scholar and click on My Profile in the upper right corner and follow the prompts. Afterwards you will have a profile that looks similar to the following. 

The number of citations, your h-index, and your i10-index are displayed in the right column.  The i10-index it a metric specifically created by Google.  The i10-index represents the number of publications with at least 10 citations.


Pros and Cons of the h-index

The idea behind the h-index was to create a simple and understandable metric that can quantify the output of researchers.  Some of the reasons that the h-index has been used for so long is because

  1. It summarizes output into a single number
  2. Does not require a minimum number of publications.
  3. Does not require tuning thresholds
  4. Easy to interpret
  5. It is a robust measure of a researcher’s impact

However, the h-index can be inflated due to an increase in the number of average authors per paper, by the number of self-citations, or older articles can still accumulate citations leading to a continual increase in  an author’s h-index even when the researcher is no longer producing papers or is deceased.


[1]          “Definitions of Criteria and Considerations for P30 Critiques.” (accessed Sep. 13, 2022).

[2]          C. Rapple, “Research impact: what it is, why it matters, and how you can increase impact potential,” Kudos, Aug. 23, 2019. (accessed Sep. 01, 2022).

[3]          J. Ravenscroft, M. Liakata, A. Clare, and D. Duma, “Measuring scientific impact beyond academia: An assessment of existing impact metrics and proposed improvements,” PLOS ONE, vol. 12, no. 3, p. e0173152, Mar. 2017, doi: 10.1371/journal.pone.0173152.

[4]          V. Koltun and D. Hafner, “The h-index is no longer an effective correlate of scientific reputation,” PLoS One, vol. 16, no. 6, p. e0253397, Jun. 2021, doi: 10.1371/journal.pone.0253397.

[5]          J. E. Hirsch, “An index to quantify an individual’s scientific research output,” Proc Natl Acad Sci U S A, vol. 102, no. 46, pp. 16569–16572, Nov. 2005, doi: 10.1073/pnas.0507655102.

[6]          R. Van Noorden and D. Singh Chawla, “Hundreds of extreme self-citing scientists revealed in new database,” Nature, vol. 572, no. 7771, pp. 578–579, Aug. 2019, doi: 10.1038/d41586-019-02479-7.

[7]          A. Y. Gasparyan, M. Yessirkepov, A. Duisenova, V. I. Trukhachev, E. I. Kostyukova, and G. D. Kitas, “Researcher and Author Impact Metrics: Variety, Value, and Context,” J Korean Med Sci, vol. 33, no. 18, Apr. 2018, doi: 10.3346/jkms.2018.33.e139.