Skip to main content

Library Subject Guides

6. Measure Impact: Author impact metrics

Advantages of the H-index

Allows for direct comparisons of researchers within disciplines

Measures quantity and impact by a single value

Attempts to minimize the influence of one or two articles that have been cited numerous times

Attempts to minimize the influence of having published numerous articles with few or no citations

Disadvantages of the H-index 

Does not give an accurate measure for early-career researchers

Calculated by using articles that are indexed in specific databases.  If a researcher publishes an article in a not indexed  the article and any citations will not be included in the the H index

The H-index cannot be compared across disciplines or different subjects. H-scores can often be higher in one field (genetics) than another field (anthropology).

Like any citation metric, H-scores are open to manipulation through practices like self-citation and citation practices that involve academics citing each others' work 

The H-index also ignores the impact of author order. Any article may be published by many authors. The H-index does not identify the position of the author on the hierarchy of author importance. 

H-scores do not evaluate the ideas presented in these highly cited papers

Author Impact - The H-index

scattergraph showing h-index

The H-index is a measure of the number of publications published by an individual and how often they are cited 

An author's h-index, or Hirsch index, is the number (integer) n for which the author has published at least n papers which have each been cited at least n times.  Eg

  • 5 papers cited 1, 2, 3, 4, 5 times: h-index is 3 (3 papers cited at least 3 times)
  • 5 papers cited 1, 1, 2, 2, 2 times: h-index is 2 (at least 2 papers cited 2 times)
  • 5 papers cited 1, 1, 1, 1, 20 times: h-index is 1 (at least 1 paper cited 1 time)


How to find your H-index

Web of Science - Select author search and Create a Citation Report
Scopus - Select author search or ORCID. click view Citation Report
Google Scholar  - Create a Google Scholar profile which will generate your h-index
Publish or Perish - Based on Google Scholar Metrics this free software can calculate a variety of author metrics
Microsoft Academic - re-activated in 2016, Microsoft's answer to Google Scholar

The H-index for any researcher changes over time

The H index is dependent on the academic area

  • The more researchers in a field, the more articles are produced and this will create more opportunities for citation and eventually hence higher H-indices.
  • Researchers in different fields also produce more papers than others, increasing the likelihood of increased citations
  • Some fields emphasize including more citations in their articles than other fields 

Who to Contact


Phone: +6433693881
Internal Phone: 93881

The G index

There are claims that the  G - index is more accurate than the H - index. It gives more weight to highly-cited articles.

G-Index is calculated by ranking a set of articles in decreasing order of the number of citations that occur.

The G-Index is the (unique) largest number that the top g articles received (together) at least g^2 citations.

Not as widely accepted as H-Index.

i10 index


Created by Google Scholar and used only in Google's My Citations feature

Another way to help calculate the productivity of a scholar.  

Very simple, free and straightforward to calculate but only used in Google Scholar