Journal-level metrics are used to evaluate an academic journal's impact and quality. Intended to reflect the place of a journal within its field, relative difficulty of being published in that journal, and the prestige associated with it.
SCImago measures the scientific influence of scholarly journals. Scientific Journal Rankings (SJR) accounts for both the number of citations received by a journal and the importance/prestige of where the journal citations come from.
SCImago Journal & Country Rank is a publicly available portal that includes the journals and scientific indicators developed from the information provided from Scopus.
The SCImago site also offers SIR (institutional rankings). The SIR is a classification of academic and research-related institutions ranked by a composite indicator that combines three different sets of indications based on research performance, innovation outputs, and societal impact measures by web visibility. See UT Health San Antonio rankings.
CiteScore, SJR, and SNIP can be found by using the Sources tab in Scopus. Search by Source name or Browse sources and select subject(s).
CiteScore - measures average citations received per document published in the serial
SJR - measures weighted citations received by the serial; depends on the subject field and prestige of citing serial
SNIP - "Source Normalized Impact per Paper" - measures actual citations received relative to citations expected for the serial's subject field
The Eigenfactor is a rating of the total importance of a scientific journal. The algorithm corresponds to the basic model of research in which readers follow chains of citations as they move from journal to journal. The frequency of journal visits gives a measure of that journal's importance within the network of academic citations. The frequency, presented as a percentage, is the Eigenfactor.
Like impact factors, the Eigenfactor gathers data from journals listed in the Journal Citation Reports. However, the algorithms used to calculate Eigenfactors are open and replicable.
**Note - the library does not subscribe to Journal Citation Reports.**
Journal impact factor measures the yearly average of citations to recent articles published. The impact factor is calculated by dividing the number of citations in the year by the total number of articles published in the previous two years. For example:
Impact factors are published annually in the Journal Citation Reports database. Impact factors are only available for journals indexed within Web of Science.
Criticisms of Impact Factor
Originally developed to help libraries choose the best journal(s) for their collection, the impact factor has morphed into a system used to place value on researchers and aid the tenure-track process. Impact factors provide metrics on the journal only and have no bearing on individual articles and/or authors. The number one criticism of the score is the inability to reproduce the metric in independent audits. The methods used to calculate a journal impact factor are proprietary and can be easily influenced by the editorial process of individual publishers.