Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2005 Nov 15;102(46):16569-72.
doi: 10.1073/pnas.0507655102. Epub 2005 Nov 7.

An index to quantify an individual's scientific research output

J E Hirsch  1
Affiliations

An index to quantify an individual's scientific research output

J E Hirsch. Proc Natl Acad Sci U S A. .

Abstract

I propose the index h, defined as the number of papers with citation number > or =h, as a useful index to characterize the scientific output of a researcher.

PubMed Disclaimer

Figures

Fig. 1.
Fig. 1.
Schematic curve of number of citations versus paper number, with papers numbered in order of decreasing citations. The intersection of the 45° line with the curve gives h. The total number of citations is the area under the curve. Assuming the second derivative is nonnegative everywhere, the minimum area is given by the distribution indicated by the dotted line, yielding a = 2 in Eq. 1.
Fig. 2.
Fig. 2.
Histogram giving the number of Nobel prize recipients in physics in the last 20 years versus their h index. The peak is at the h index between 35 and 39.
See this image and copyright information in PMC

References

    1. Laherrere, J. & Sornette, D. (1998) Eur. Phys. J. E Soft Matter B2, 525–539.
    1. Redner, S. (1998) Eur. Phys. J. E Soft Matter B4, 131–134.
    1. Redner, S. (2005) Phys. Today 58, 49–54.
    1. van Raan, A. F. J. (2004) Scientometrics 59, 467–472.
    1. King, C. (2003) Sci. Watch 14, no. 5, 1.