Bibliometrics: CiteScore (Scopus)
The average citation level of a journal is an extremely limited indicator, and is not a replacement for expert, qualitative assessment of the journal. The distribution of citations is typically skewed, therefore using the mean is problematic. Many articles published in "high impact" journals receive very few or indeed no citations at all. Many factors can influence citation rates such as language, journal history, publication schedule, and subject specialty and scope.
Other factors which can affect a journal's ranking or metrics include:
- article type(s)
- changes in journal format
- title changes
- cited-only journals (i.e. whereby references from a journal (including self-citations) are not included in the dataset)
Many of the journals in Web of Science and Scopus are English-language from North America, Western Europe and Australia. Irish journals in many research areas can be underrepresented.
Review journals and original research journals are treated the same even though the citation patterns of these types of articles differ.
What is CiteScore
CiteScore is a set of journal metrics produced by Elsevier and calculated using citation data from Scopus. A journal's CiteScore represents the average number of citations received in the CiteScore year (e.g. 2015), by papers published in the three preceding years (e.g. 2012, 2013 and 2014). In contrast, the Journal Impact Factor (Clarivate Analytics) uses a two year, rather than three year, window. All types of documents (research articles, review articles, conference proceedings, editorials errata, letters, notes, and short surveys) are included in the CiteScore calculation. Although articles in press are included in Scopus they are not included in the calculation. CiteScore rankings and CiteScore percentile metrics are also available.
CiteScore metrics (along with the SJR and SNIP) can be viewed on Scopus or through Elsevier's Journal Metrics website.
Example of CiteScore
Source: journalmetrics.com (Elsevier)