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Graduate Help: Journal Metrics

Journal Metrics

There are many journal metrics, measuring citations in a specific journal over time. Here are some common metrics:

Impact Factor: "The journal Impact Factor is the average number of times articles from the journal published in the past two years have been cited in the Journal Citation Reports (JCR) database year" (JCR, 2014).

5-Year Journal Impact Factor: The average number of times articles from the journal published in the most recent 5 years have been cited.

Journal Immediacy Index: The average number of times articles from the journal published in the current year have been cited.

SJR - SCImago Journal Rank: The measure of a journal's scientific influence based on the number of incoming citations and the importance of the journals those citations come from.

SNIP - Source Normalized Impact per Paper: "measures contextual citation impact by weighting citations based on the total number of citations in a subject field." - Scopus

IPP - Impact per Publication: "measures the ratio of ciations in a year to scholarly papers published in the three previous years divided by the number of scholarly papers published in those same years." -Scopus

Eigenfactor: Eigenfactor uses the number of incoming citations to measure a journal’s importance to the scientific community, with citations from higher ranking journals weighted to make a larger contribution than those of poorly ranked journals.

Journal Metric Sources

Scopus is an interdisciplinary database that is used to calculate SJR, SNIP, and IPP.

Journal Citation Reports (InCites) provides the journal impact factor, 5-year journal impact factor, and journal immediacy index.


Journal Impact Factors usages

There are many uses for journal impact factors:

  • to compare journals within a field to see which journal may have a greater impact on the field
  • researchers/scientists may use impact factor as one of their deciding criteria for article submission
  • some universities are using impact factor to measure scholarly output for their researchers and departments
  • some universities are asking professors to provide impact factors as part of their tenure/promotion portfolio
  • some funding agencies are asking researchers to provide impact factors
  • some libraries are using journal impact factor and the rankings to make decisions on journal retention and/or acquisitions
  • journals are using impact factor to attract editors, funding/sponsorships, and author submissions