Thomson Reuters' Journal Citation Reports (JCR) is a valuable resource that quantifies the citation impact of the major peer reviewed scholarly journals. The JCR currently covers nearly 8,000 journals and are published each year around June/July. Since its publication last year the information has been enhanced considerably .
The new enhancements include a five-year impact factor. This five-year impact factor uses a five-year publication and citation window rather than the standard two years, thus providing a broader range of citation activity. The five-year impact is more of an appropriate time frame for most researchers in Wageningen when selecting a journal for publication.
In addition to the impact factor, the JCR now includes the Eigenfactor Metrics, which use citing journal data from the entire JCR file to reflect the prestige and citation influence of journals by considering scholarly literature as a network of journal-to-journal relationships. Eigenfactors of journals and their relationships are graphically displayed at http://well-formed.eigenfactor.org. Other enhancements include a better presentation of the journal Self citations and box plots on how a journal ranks in different categories.
Over the last few years, a number of competing products, free and fee based, have tried to come up with new and competing journal ranking measures. First, there are the journal ranking data from Thomson’s Essential Science Indicators based on a 10-year time frame and the abovementioned Eigenfactor Metrics from the University of Washington. Of a more recent date are the Scimago Journal Rankings based on Scopus data and the journal analyzer from Scopus itself. An interesting website with regard to journal information is Journal Info from the University of Lund.