/ Get Help / Visibility of Research / Citation Analyses /

The H-Index

The h-index is a quantitative indicator invented by physicist Jorge Hirsch in 2005 that enables the simultaneous evaluation of a researcher's productivity in terms of publishing articles and the significance of his or her publications. The h-index is database-specific, so it is calculated only from citations included in that database. Thus, one researcher may have different h indices in the Web of Science, Scopus and Google Scholar/Publish or Perish databases. 

Example of calculating the h-index

If the researcher has fifteen (15) publications in the database, four of which have been cited in four or more publications by other authors included in the database, and the remaining eleven publications have been cited fewer times or not at all, the h-index of the researcher is four (4). 

Quick instructions for calculating the h-index

In citation databases the h-index is calculated automatically based on the selected pool of publications. When you search the database for your own name, you will see a list of publications. Check that you are indeed the author and remove any publications written by others. Next, click on the “Create Citation Report" button (Web of Science users) or the “View Citation Overview” button (Scopus users). The Publish or Perish application shows your h-index and the number of your publications and citations automatically.

Using the h-index

Effects of the researcher's age and career length

The researcher’s age and the length of his or her career affect the h-index. Researchers who have been active in academia for a long time have published more works and, most likely, have been referred to more frequently than junior researchers. The length of the researcher’s career must be taken into consideration when using the h- index. Hirsch himself stated that the h-index should grow in a roughly linear fashion over the course of the researcher's career.

Comparison between researchers in the same field and with similar research interests

The h-index is useful only for comparing researchers in the same field with similar research interests. The h- indexes of researchers in the field of medicine, the humanities or social sciences should not be compared, because different fields have different practices for publishing and citing previous publications and the scope of citation databases varies across different fields. Medicine and the natural sciences have the most extensive and up-to-date databases.