Metrics

CiteScore measures the average citations received per document published in a title. CiteScore values are based on citation counts in a range of four years (e.g. 2017-2020) to peer-reviewed documents (articles, reviews, conference papers, data papers and book chapters) published in the same four calendar years, divided by the number of these documents in these same four years (e.g. 2017-20).

For example, CiteScore 2020:

A = Citations to articles, reviews, conference papers, data papers and book chapters published in 2017-2020

B = Sum of articles, reviews, conference papers, data papers and book chapters published in 2017-2020

2020 CiteScore = A/B

A CiteScore is available for most active serial titles on Scopus - peer-reviewed journals, book series, conference proceedings and trade journals.

SCImago Journal Rank (SJR) is a measure of the number of times an average paper in a particular journal is cited, and as such is conceptually similar to the Impact Factor. A major difference is that instead of each citation being counted as one, as with the Impact Factor, the SCImago Journal Rank assigns each citation a value greater or less than 1.00 based on the rank of the citing journal. The weighting is calculated using a three-year window of measurement and uses the Scopus database. Authors can use these metrics when deciding where to publish.

The idea is to assign weights to bibliographic citations based on the importance of the journals that issued them. Citations issued by more important journals will be more valuable than those issued by less important ones. This 'importance' will be computed recursively, i.e., the important journals will be those which in turn receive many citations from other important journals.