Journal level metrics evaluate the impact of a particular publication by incorporating the number of times articles within that publication have been cited as part of a calculation. Each metric has its own formula for calculation and aims to provide a number to represent a particular aspect of impact.
Journal Impact Factor and CiteScore are two frequently used metrics for measuring how much a particular article has been cited over a period of time. Here are several differences between the two:
- Journal Impact Factor is a proprietary metric created by Clarivate (which owns Web of Science and Journal Citations Report), and is based on Web of Science data. CiteScore is a proprietary metric created by Elsevier (which owns Scopus) and is based on Scopus data.
- Journal Impact Factor uses a 2-year window for their calculations. CiteScore uses 3 years.
- CiteScore includes all document types indexed by Scopus (which includes articles, reviews, letters, notes, editorials, conference papers, etc.) while Journal Impact Factor only includes "citable documents" which are articles and reviews.
Source
Additional metrics that are worth considering besides CiteScore and Journal Impact Factor:
- Eigenfactor Score - "The Eigenfactor Score calculation is based on the number of times articles from the journal published in the past five years have been cited in the JCR year, but it also considers which journals have contributed these citations so that highly cited journals will influence the network more than lesser cited journals. References from one article in a journal to another article from the same journal are removed, so that Eigenfactor Scores are not influenced by journal self-citation." Find an Eigenfactor Score using the Eigenfactor website.
- SCImago Journal Rank (SJR) is "a measure of scientific influence of scholarly journals that accounts for both the number of citations received by a journal and the importance or prestige of the journals where such citations come from." Find SJR in Scopus or on Elsevier's Journal Metrics website.
- Source Normalized Impact per Paper (SNIP) is a metric that measures a journal's "contextual citation impact by weighting citations based on the total number of citations in a subject field." SNIP is the "ratio of the journal's citation count per paper and the citation potential in its subject field." Find SNIP in Scopus or on Elsevier's Journal Metrics website.
