Journal Cited Half-Life: According to Thomson Reuters it is, "The median age of the articles that were cited in the JCR year. Half of a journal's cited articles were published more recently than the cited half-life. For example, in JCR 2001 the journal Crystal Research and Technology has a cited half-life of 7.0. That means that articles published in Crystal Research and Technology between 1995-2001 (inclusive) account for 50% of all citations to articles from that journal in 2001.
Only journals cited 100 or more times in the JCR year have a cited half-life.
A higher or lower cited half-life does not imply any particular value for a journal. For instance, a primary research journal might have a longer cited half-life than a journal that provides rapid communication of current information. Cited half-life figures may be useful to assist in collection management and archiving decisions. Dramatic changes in cited half-life over time may indicate a change in a journals format. Studying the half-life data of the journals in a comparative study may indicate differences in format and publication history. "
This resource is a "portal that includes the journals and country scientific indicators developed from the information contained in the Scopus database. These indicators can be used to assess and analyze scientific domains.
This platform takes its name from the SCImago Journal Rank (SJR) indicator, developed by SCImago from the widely known algorithm Google PageRank™. This indicator shows the visibility of the journals contained in the Scopus database from 1996."
According to eigenFACTOR.org it is "an academic research project co-founded by Jevin West and Carl Bergstrom and sponsored by the Bergstrom Lab in the Department of Biology at the University of Washington. We aim to use recent advances in network analysis and information theory to develop novel methods for evaluating the influence of scholarly periodicals and for mapping the structure of academic research.'