Skip to Main Content
Nova southeastern University logo Martin and Gail Press NSU Health Library Logo

Nutrition: Eigenfactor

What is Eigenfactor?

The Eigenfactor came out of the Metrics Eigenfactor Project in 2008, a bibliometric research project conducted by Professor Carl Bergstrom and his laboratory at University of Washington.

The Eigenfactor Score measures the number of times articles from the journal published in the past five years have been cited in the Journal Citation Reports (JCR) year.

Like the Impact Factor, the Eigenfactor Score is essentially a ratio of number of citations to total number of articles. However, unlike the Impact Factor, the Eigenfactor Score:

  • Counts citations to journals in both the sciences and social sciences.
  • Eliminates self-citations. Every reference from one article in a journal to another article from the same journal is discounted.
  • Weights each reference according to a stochastic measure of the amount of time researchers spend reading the journal.

Eigenfactor scores are scaled so that the sum of the Eigenfactor scores of all journals listed in Thomson's Journal Citation Reports (JCR) is 100. 

The Eigenfactor uses Thomson Reuters Web of Science citation data.

Further Reading:

What does Eigenfactor Mean?

Eigenscore on Journal Citation Reports

Eigenfactor and Article Influence

A journal's Eigenfactor score is measured as its importance to the scientific community.  Scores are scaled so that the sum of all journal scores is 100.  In 2006, Nature had the highest score of 1.992.  

  • Intended to reflect the influence and prestige of journals.  
  • Created to help capture the value of publication output vs. journal quality (i.e. the value of a single publication in a major journal vs. many publications in minor journals).

Article Influcence Score

The mean Article Influence Score is 1.00.  An Article Influence Score greater than 1.00 indicates that the articles in a journal have an above-average influence.

  • Measures the average influence, per article, of the papers published in a journal.  
  • Calculated by dividing the Eigenfactor by the number of articles published in the journal.  

Advantages of Eigenfactor/Article Influence Score:

  • Can be accessed for free.
  • Includes a built-in evaluation period of five years.
  • Attempts to give a more accurate representation of the merit of citations than do raw citation counts.

Disadvantages of Eigenfactor/Article Influence Score:

  • Eigenfactor assigns journals to a single category, making it more difficult to compare across disciplines.
  • Some argue that Eigenfactor score isn't much different than raw citation counts (see this blog post, for example).

Below is an example of the Eigenfactor and Article Influence Scores for a few journals.  You can search the Eigenfactor Website to find the scores for journals of interest.