From The Embassy of Good Science


What is this about?

The h-index, introduced by Jorge Hirsch in 2005, is a metric that conveys both the productivity and citation impact of an individual researcher. [1] If a researcher has a h-index of 5 then the researcher has 5 publications with 5 or more citations. A h-index of 75 means that there are 75 publications with 75 or more citations. It thus becomes progressively more difficult to increase one’s h-index, and h-indices are exponentially distributed among scientists.

  1. Hirsch JE. An index to quantify an individual's scientific research output. Proceedings of the National academy of Sciences 2005;102(46):16569-16572.

Why is this important?

The h-index was partially introduced as an improvement over simply counting the quantity of a researcher’s publications. A researcher with 10 publications may have a higher h-index than a researcher with 100 publications.

However, as with any other metric, it is possible to ‘game’, or artificially increase, one’s h-index. Some well-established strategies include:

  • Self-citation (cf. Italian scientists increase self-citations in response to promotion policy [1]
  • Honorary authorship (putting a distinguished researcher on an authorship list often increases citation)
  • Publishing on ‘hot topics’
  • Writing review papers (often more cited than original studies)

Any aspect of citation bias can be taken advantage of for improving h-index.

  1. Chawla DS. Italian scientists increase self-citations in response to promotion policy. 2018; Available at: https://www.natureindex.com/news-blog/italian-scientists-increase-self-citations-in-response-to-promotion-policy. Accessed 29 May, 2019.

For whom is this important?

Other information

Good Practices & Misconduct