The SCImago Journal Rank (SJR) indicator is a measure of the prestige of

scholarly journal An academic journal (or scholarly journal or scientific journal) is a periodical publication in which scholarship relating to a particular academic discipline is published. They serve as permanent and transparent forums for the dissemination, scr ...

s that accounts for both the number of

citation A citation is a reference to a source. More precisely, a citation is an abbreviated alphanumeric expression embedded in the body of an intellectual work that denotes an entry in the bibliographic references section of the work for the purpose o ...

s received by a journal and the prestige of the journals where the citations come from.

Etymology

SCImago is not an

acronym An acronym is a type of abbreviation consisting of a phrase whose only pronounced elements are the initial letters or initial sounds of words inside that phrase. Acronyms are often spelled with the initial Letter (alphabet), letter of each wor ...

, although the capitalization of first 3 letters do stand for SCientific Influence. The suffix "mago" appears to be randomly chosen.

Rationale

Citations are an indicator of popularity of scientific works and can be perceived as endorsement; prestige can be understood as a combination of the number of endorsements and the prestige of the works publishing them. Adopting this view, the ''SJR indicator'' assigns different values to citations depending on the perceived prestige of the journals where they come from. However, studies of methodological quality and reliability have found that "reliability of published research works in several fields may be decreasing with increasing journal rank", contrary to widespread expectations. The calculation of the ''SJR indicator'' is similar to the '' Eigenfactor score'', with the former being based on the

Scopus Scopus is a scientific abstract and citation database, launched by the academic publisher Elsevier as a competitor to older Web of Science in 2004. The ensuing competition between the two databases has been characterized as "intense" and is c ...

database and the latter on the

Web of Science The Web of Science (WoS; previously known as Web of Knowledge) is a paid-access platform that provides (typically via the internet) access to multiple databases that provide reference and citation data from academic journals, conference proceedi ...

database, and there are other differences.

Computation

A journal's SJR indicator is a numeric value representing the average number of weighted citations received during a selected year per document published in that journal during the previous three years, as indexed by

. Higher SJR indicator values are meant to indicate greater journal prestige. SJR is developed by the Scimago Lab, originated from a research group at the

University of Granada The University of Granada (, UGR) is a public university located in the city of Granada, Spain, and founded in 1531 by Emperor Charles V. With more than 60,000 students, it is the fourth largest university in Spain. Apart from the city of Granad ...

. The SJR indicator is a variant of the eigenvector centrality measure used in network theory. Such measures establish the importance of a node in a network based on the principle that connections to high-scoring nodes contribute more to the score of the node. The SJR indicator has been developed to be used in extremely large and heterogeneous journal citation networks. It is a size-independent indicator and its values order journals by their "average prestige per article" and can be used for journal comparisons in science evaluation processes. The SJR indicator is a free journal metric inspired by, and using an algorithm similar to,

PageRank PageRank (PR) is an algorithm used by Google Search to rank web pages in their search engine results. It is named after both the term "web page" and co-founder Larry Page. PageRank is a way of measuring the importance of website pages. Accordin ...

. The SJR indicator computation is carried out using an iterative

algorithm In mathematics and computer science, an algorithm () is a finite sequence of Rigour#Mathematics, mathematically rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algo ...

that distributes prestige values among the journals until a steady-state solution is reached. The SJR algorithm begins by setting an identical amount of prestige to each journal, then using an iterative procedure, this prestige is redistributed in a process where journals transfer their achieved prestige to each other through citations. The process ends up when the difference between journal prestige values in consecutive iterations do not reach a minimum threshold value any more. The process is developed in two phases, (a) the computation of ''Prestige SJR'' (''PSJR'') for each journal: a size-dependent measure that reflects the whole journal prestige, and (b) the normalization of this measure to achieve a size-independent measure of prestige, the ''SJR indicator''. In addition to the network-based SJR indicator, the SJR also provides a more direct alternative to the

impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ...

(IF), in the form of average citations per document in a 2-year period, abbreviated as ''Cites per Doc. (2y)''.

Results

The SCImago web site gives both the SJR and H index, and the results are quite different. Here are the journals ranking in the top three for each of the metrics.

References

External links