From this week’s issue of Nature, a news story by Declan Butler “Free journal-ranking tool enters citation market” (Nature , 451, 6; 2008)

“A new Internet database lets users generate on-the-fly citation statistics of published research papers for free. The tool also calculates papers’ impact factors using a new algorithm similar to ”https://en.wikipedia.org/wiki/PageRank">PageRank, the algorithm Google uses to rank web pages. The open-access database is collaborating with Elsevier, the giant Amsterdam-based science publisher, and its underlying data come from Scopus, a subscription abstracts database created by Elsevier in 2004.

The SCImago Journal & Country Rank database was launched in December by SCImago, a data-mining and visualization group at the universities of Granada, Extremadura, Carlos III and Alcalá de Henares, all in Spain. It ranks journals and countries using such citation metrics as the popular, if controversial, Hirsch Index. It also includes a new metric: the SCImago Journal Rank (SJR)."

The article goes on to discuss the new metric, and to compare it with others, notably the dominant Impact Factor of Thomson Scientific. Thomson has set up a web forum to respond formally to an editorial in the Journal of Cell Biology, in which Mike Rossner and colleagues point to discrepancies between their “independent audit” calculations of Impact Factors based on Thomson data, and Thomson’s own calculated Impact Factors from the same data.