What is the h index

Publishing at the TU Berlin

With the H-Index, a person-related indicator is increasingly establishing itself in science evaluation. It was named after its developer Jorge E. Hirsch; The synonyms Hirsch factor or Hirsch index are also common. It was developed to use citations to evaluate and compare the scientific performance of an individual researcher. In contrast to the Journal Impact Factor, the H-Index can actually be used as an instrument for (quantitative) evaluation of the publication performance of individual scientists.

What is the H index?

The H-Index is calculated from the number of publications by an author and the frequency with which the articles are cited. The citation databases Web of Science or Scopus but also Google Scholar can serve as a database.

The H index H of a scientist is defined as the (largest possible) number of publications by this scientist, which at least H times have been quoted. A scientist has a Hirsch index H, if H of the total N Publications at least Htimes and the remaining (NH) Publications at most H-were quoted times.

The following examples are from the Wikipedia article on the H index:

If the quotation frequency is 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, the H-Index is 5 because five publications were cited at least five times and the rest were cited at most five times.




If the quotation frequency is 100, 100, 2, 2, 2, 2, 2, 2, 2, 2, the H-Index is 2 because two publications were cited at least twice, the rest at most twice.




If the quotation frequency is 100, 100, 9, 8, 3, 2, 2, 1, 1, 0, the H-Index is 4 because four publications were cited at least four times and the rest were cited at most four times.




For a high H index, not only must as many articles as possible be published, but as many of them as possible also have to be cited as often as possible.

Advantages and disadvantages of the H index

The great advantage of the H-Index is its robustness. It cannot be manipulated as easily as the Journal Impact Factor (JIF).

One point of criticism of the H-Index, however, is the discrimination against young scientists. They generally have a lower H-index because they have generally published less than researchers who have been working in the same subject for a long time.

With the H-Index, too, it must be noted that the different publication behavior of the various specialist disciplines leads to different indices that are not interdisciplinary comparable. In addition, the H-Index - like the JIF - is only a quantitative assessment parameter that should not be used for the qualitative assessment of scientists.

Contact for questions

How you can determine your H-index, we show in the tutorial for the determination of bibliometric key figures.

If you have any questions about the H-Index or bibliometrics in general, please do not hesitate to contact us or visit the website for more information.