The SCImago Journal Rank (SJR) indicator is a measure of the 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 the citations come from. A journal's SJR is a numeric value indicating the average number of weighted citations received during a selected year per document published in that journal during the previous three years. Higher SJR values are meant to indicate greater journal prestige.
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.
In addition to the network-based SJR indicator, the SJR also provides a more direct alternative to the impact factor (IF), in the form of average citations per document in a 2-year period, abbreviated as Cites per Doc. (2y).