Citation Research & Impact Metrics

Journal Impact Factor (JIF)

The Journal Impact Factor (JIF) is defined as all citations to the journal in the current Journal Citation Reports (JCR) year to items published in the previous two years, divided by the total number of items published in the journal in the previous two years.

Calculation of Journal Impact Factor (JIF) in the Year 2020:

Note:

• JIF of 2.0 means that on average, the items published one or two years ago have been cited two times.
• The citing works may be items published in the same journal or they may be from different journals, proceedings or books indexed in Web of Science Core Collection.
• Not all journal have a JIF, they must be indexed in JCR, which covers journals listed in Science Citation Index Expanded (SCIE) and/or Social Sciences Citation Index (SSCI) of Web of Science.

5-Year Impact Factor

The 5-year Impact Factor is the average number of times items from a journal published in the last five years have been cited in the JCR year (as compared to the last 2 years for JIF).

Calculation of 5-Year Impact Factor in the Year 2020:

Note:

• The 5-Year IF should not be thought of in terms of “multi-year” Impact Factor. While it does consider multiple cited years, the 5-Year IF uses data from just one citing year (the year of the edition).
• A journal with only 2 or 3 years of publication will have a 5-Year IF equal to a 2-Year IF because the previous years of items counts are known to be zero. A journal that has additional years of publication but no additional years of coverage in Web of Science will have a 2-Year IF but no 5-Year IF since the additional data-elements required for the 5-Year IF calculation are not known. 

SCImago Journal & Country Rank (SJR) is a set of journal metrics generated using citation data from Scopus which calculates the average number of weighted citations received in year over the number of articles published in the previous three years.