Apr
2nd
Thu
2nd
1:27 am
This is one of the interactive graphics Eigenfactor.org has published as part of their effort to draw more meaningful conclusions from the citation network of published research. Their analysis, described here and in this PDF, uses an eigenvector centrality measure similar to PageRank to evaluate the relationships between articles.
Incidentally, Jack July recently posted a similarly intended graphic from Nature (full text available free here). Its authors use clickstream logs to create a map of greater resolution and timeliness than is possible with citation data.