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Several indicators evaluate the impact or reputation of a journal. They are based on the number of citations of a journal over a specific period of time.
It can be useful to identify:
Keep in mind:
The calculation of the Impact factor (IF) for journal X in 2017
Total number of citations received by journal X in 2017 by all content published in 2015-2016 (last 2 years)
Impact Factor = ____________________________________________________________________________________________
Total number of articles & reviews published in journal X between 2015-2016 (last 2 years)
A five-year coverage impact factor also exists.
Source of data: the IF is based on data from the Web of Science Core Collection database (owned by Clarivate Analytics)
Where to find this indicator:
Keep in mind the impact factor:
Eigenfactor is the average number of citations a journal has received over the last 5 years in the Journal Citation Reports. The two main differences between the Impact Factor and the Eigenfactor are:
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 top thousand journals have an Eigenfactor above 0.01 and a journal like The American Economic Review which has been in the top 10 journals in social sciences, could reach an Eigenfactor of 0.09701.
Source of data: Web of Science Core Collection (owned by Clarivate Analytics)
Where to find this indicator:
Keep in mind:
Scimago measures the average number of citations for a journal over the last 3 years. It takes the quality and reputation of journals into account, using an algorithm similar to Google's Page Rank.
Source of data: Scopus database (owned by Elsevier).
Where to find this indicator:
Scimago: freely accessible
Keep in mind:
The SNIP is the average number of citations for a journal over the last 3 years. This metric weights citations based on the citation patterns in a subject field.
Source of data: Scopus database (owned by Elsevier)
Where to find this indicator:
Keep in mind:
Eliminates self citation | Journal reputation | Subject Field | |
---|---|---|---|
Impact Factor | no | no | no |
Eigenfactor | yes | yes | no |
Scimago | no | yes | no |
SNIP | no | no | yes |
Comparison of databases
Scopus contains more titles in the Social Sciences than Web of science; Nevertheless in both databases English journals are over represented.