Eigenfactor : Does the Principle of Repeated Improvement Result in   Better Journal Impact Estimates than Raw Citation Counts?
  Eigenfactor.org, a journal evaluation tool which uses an iterative algorithm to weight citations (similar to the PageRank algorithm used for Google) has been proposed as a more valid method for calculating the impact of journals. The purpose of this brief communication is to investigate whether the principle of repeated improvement provides different rankings of journals than does a simple unweighted citation count (the method used by ISI). 
Philip M. Davis