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CEU Library, Central European University

Scholarly Research Impact Metrics

Author Level Impact


The h-index is a metric that informs about the productivity and the impact of the published work. Calculate the h-index is relatively easy. h is the number of articles that have each been cited h number of times. 

This means an author with a h-index of 15 has published 15 articles that have each been cited at least 15 times.

Depending on the used data basis, the H index can differ. The databases of Google, SCOPUS and Web of Science are using different journals published in different time periods.

Let’s compare the h-index of cognitive scientist Gergely Csibra at Google Scholar, Scopus and Web of Science.

Google Scholar

Google Scholar example

SCOPUS example

Web of Science

Web of Science example

Further reading:
J. E. Hirsch: An index to quantify an individual’s scientific research output. In: PNAS November 15, 2005 102 (46) 16569-16572


For using H-index as a metric, the following should be kept in mind:

  • Compared scientists should be from the same academic discipline.
  • The h-index depends on the stage of career of scientists.
  • The source for calculation should be recognized.
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