Citation metrics and Impact Factor

Citation Metrics of the American Academic & Scholarly Research Journal using Publish or Perish citation and impact factor software: Harzing, A.W. (2007) Publish or Perish, available from

Query date: 2016-01-20
Papers: 405
Citations: 225
Years: 9
Cites/year: 25
Cites/paper: 0.56
Cites/author: 153.42
Cites/author/year: 9.97
Papers/author: 262.90
Authors/paper: 1.97

h-index: 5 (39%)
g-index: 10 (47%)
e-index: 7.07
hc-index: 6
hI-index: 3.13
hI,norm: 4
hI,annual: 0.50
hm-index: 4.08
AW-index: 7.91
AWCR: 62.61
AWCRpA: 41.91

Hirsch a=9.00, m=0.56
Contemporary ac=6.94

Citation Metrics Explained

In addition to the various simple statistics (number of papers, number of citations, and others), Publish or Perish calculates the following citation metrics (see Citation metrics in the online help file for more details):

Hirsch’s h-index
Proposed by J.E. Hirsch in his paper An index to quantify an individual’s scientific research outputarXiv:physics/0508025 v5 29 Sep 2005. It aims to provide a robust single-number metric of an academic’s impact, combining quality with quantity.
Egghe’s g-index
Proposed by Leo Egghe in his paper Theory and practice of the g-indexScientometrics, Vol. 69, No 1 (2006), pp. 131-152. It aims to improve on the h-index by giving more weight to highly-cited articles.
Zhang’s e-index
Publish or Perish also calculates the e-index as proposed by Chun-Ting Zhang in his paper The e-index, complementing the h-index for excess citationsPLoS ONE, Vol 5, Issue 5 (May 2009), e5429. The e-index is the (square root) of the surplus of citations in the h-set beyond h2, i.e., beyond the theoretical minimum required to obtain a h-index of ‘h’. The aim of the e-index is to differentiate between scientists with similar h-indices but different citation patterns.
Contemporary h-index
Proposed by Antonis Sidiropoulos, Dimitrios Katsaros, and Yannis Manolopoulos in their paper Generalized h-index for disclosing latent facts in citation networksarXiv:cs.DL/0607066 v1 13 Jul 2006. It aims to improve on the h-index by giving more weight to recent articles, thus rewarding academics who maintain a steady level of activity.
Age-weighted citation rate (AWCR) and AW-index
The AWCR measures the average number of citations to an entire body of work, adjusted for the age of each individual paper. It was inspired by Bihui Jin’s note The AR-index: complementing the h-indexISSI Newsletter, 2007, 3(1), p. 6. The Publish or Perish implementation differs from Jin’s definition in that we sum over all papers instead of only the h-core papers.
Individual h-index (original)
The Individual h-index was proposed by Pablo D. Batista, Monica G. Campiteli, Osame Kinouchi, and Alexandre S. Martinez in their paperIs it possible to compare researchers with different scientific interests?Scientometrics, Vol 68, No. 1 (2006), pp. 179-189. It divides the standard h-index by the average number of authors in the articles that contribute to the h-index, in order to reduce the effects of co-authorship.
Individual h-index (PoP variation)
Publish or Perish also implements an alternative individual h-index called hI,norm that takes a different approach: instead of dividing the total h-index, it first normalizes the number of citations for each paper by dividing the number of citations by the number of authors for that paper, then calculates the h-index of the normalized citation counts. This approach is much more fine-grained than Batista et al.’s; we believe that it more accurately accounts for any co-authorship effects that might be present and that it is a better approximation of the per-author impact, which is what the original h-index set out to provide.
Multi-authored h-index
A further h-like index is due to Michael Schreiber and first described in his paper To share the fame in a fair way, hm modifies h for multi-authored manuscriptsNew Journal of Physics, Vol 10 (2008), 040201-1-8. Schreiber’s method uses fractional paper counts instead of reduced citation counts to account for shared authorship of papers, and then determines the multi-authored hm index based on the resulting effective rank of the papers using undiluted citation counts.
Average annual increase in the individual h-index
As of release 4.3 Publish or Perish also calculates the average annual increase in hI,norm, called hI,annual. This average annual increase in the individual h-index is useful for the following reasons:

  • In common with the hI,norm index, it removes to a considerable extent any discipline-specific publication and citation patterns that otherwise distort the h-index.
  • It also reduces the effect of career length and provides a fairer comparison between junior and senior researchers.

The hI,annual is meant as an indicator of an individual’s average annual research impact, as opposed to the lifetime score that is given by the h-index or hI,norm.

Harzing, A.W. (2007) Publish or Perish, available from