On June 30, 2021, the 2020 Journal Citation Ranking (JCR) had been published. The most striking feature was a new citation index, the Journal Citation Indicator (JCI). Szomszor [1] announced on Clarivate’s blog, “The JCI provides a single journal-level metric that can be easily interpreted and compared across disciplines. The value of the JCI is the mean Category Normalized Citation Impact (CNCI) for all articles and reviews published in a journal in the preceding 3 years” [1]. The main difference between the JCI and the Journal Impact Factor (JIF) is that the denominator of the JCI is the number of reviews and articles for only the most recent 3 years, while the numerator is the citations of those reviews and articles for 4 years, including the current year. A JCI value of 1.0 corresponds to the mean value of each category of journals in the Web of Science Core Collection. A JCI value of 2 indicates that the citation impact of a journal in the corresponding category is 2 times the mean value., whereas a JCI value of 0.5 means that a journal’s impact is half of the mean value in the corresponding category.
[1] Szomszor M. Philadelphia (PA): Clarivate; 2021. Introducing the Journal Citation Indicator: a new, field-normalized measurement of journal citation impact [Internet] [cited 2021 Jul 11].