Eigenfactor & Article Influence
|Year||Eigenfactor||Normalized Eigenfactor||Article Influence|
The Eigenfactor score is a rating of the importance of a specific journal. Journals are rated according to the number of incoming citations, with citations from highly ranked journals weighted to make a larger contribution to the Eigenfactor than those from lower ranked journals. As a measure of importance, the Eigenfactor score scales with the total impact of a journal. Journals generating higher impact to their subject field tend to have larger Eigenfactor scores. The Eigenfactor approach is thought to be more robust than the Impact Factor metric, which counts purely incoming citations without considering the significance of those citations.
Note that the Eigenfactor score is calculated using data from the Web of Science database and that journal self-citations are excluded from the calculation.
The Normalized Eigenfactor score is the Eigenfactor score which is normalized by rescaling the total number of journals in Clarivate Analytics' Journal Citation Reports (JCR) each year, so that the average journal has a score of 1.00000. Journals can then be compared and influence measured by their score relative to 1.00000. For example, if a journal has a Normalized Eigenfactor score of 5.00000, that journal is considered to be 5 times as influential as the average journal in the JCR.
The Article Influence score is a measure of the average influence of the articles published in a particular journal in the first five years after publication. It is calculated by dividing the Eigenfactor score by the percentage of all articles published in the journal normalized as a fraction of all articles recorded in all publications in the JCR. For example, the 2018 Article Influence for a journal is calculated as follows:
- A = 2018 Eigenfactor score x 0.01
- B = journal article count from 2013, 2014, 2015, 2016 and 2017 divided by the total article count from all journals in the JCR in those same years
- 2018 Article Influence = A/B
The Article Influence score is similar to Clarivate Analytics' 5-Year Impact Factor as it represents a ratio of a journal's citation influence to a journal's total article contribution over a period of five years. However, as the Article Influence score is based on the Eigenfactor score, it considers the significance of citations based on the importance of the citing journal. In addition to this, Article Influence scores are normalized so that the mean article in the entire JCR database has an Article Influence of 1.000. An Article Influence score above 1.000 then indicates that the articles in the journal have an above-average influence, whereas a score below 1.000 means that they have a below-average influence.