Skip to main content

Measuring Research Impact

An introduction to some commonly used metrics for determining the influence of published research.

Publication Count

Measuring author impact begins with looking at the publication count, or the number of academic publications he or she has written.

Publication Count

Pros Cons
  • Snap shot of raw productivity (assumes more publications = better)
  • Does not look at the quality of the contribution
  • May be difficult to distinguish authors with the same name
  • Encourages "salami" or least publishable unit publication

 

Citation Count

Looks at how many times articles written by an author have been cited in other articles. Also called "times cited" or "cited references".

Citation Count 

Pros Cons
Provides an iea of impact of an author/article based on use in other publications

Different cited reference counts can occur, dependign on which source is used
--Google Scholar is known to "over count" or mis-attribute citations which resuls in an inflated number

Does not account for use that does not result in a bibliography entry

Not every database provides citation counts

History of Citation Counting - The Science Citation Index, (SCI) founded by Dr. Eugene Garfield in 1960, was a pioneer effort in citation analysis.

Citation counts are available in Scopus.​

h-index

The h-index was devised by Prof. Jorge Hirsch, a physicist.

Individual researchers are assigned h-index score, which is supposed to reflect influence more accurately than other metrics do.

h-index scores are computed in this way: An author's publications are ranked according to the citations they received, from highest to lowest. The h-index score is that point in the ranking which equals the number of citations the item has received. So, if an author having 11 citations to the 11th publication in the list would have an h-index of 11.

  • Scopus allows the ranking of author's publications by number of citations and so allows the direct computation of the h-index score.
Pros Cons

Provides a number to quantify scholarly activity

Attempts to balance publication count and citation counts

Not an absolute value as citation counts can vary depending on the source searched
(h-index in Scopus may be different than the h-index from Google Scholar or Web of Science)