Eigenfactor® is a calculation “based on the number of times articles from the journal published in the past five years have been cited in the Journal Citation Reports® (JCR) year, but it also considers which journals have contributed these citations so that highly cited journals will influence the network more than lesser cited journals. References from one article in a journal to another article from the same journal are removed, so that Eigenfactor® Scores are not influenced by journal self-citation.” (Thomson Reuters)
How the Eigenfactor is Determined
The Eigenfactor® score of a journal is found through an estimate of the percentage of time that library users spend with that journal. It is thought that the amount of time a researcher spends with a journal measures the journal's importance within the network of academic citations.