5. The method of claim 3 , wherein the respective subsets of the set of document identification tags associated with each tier monotonically increase with the position of the tier in the ordering; and wherein the respective predetermined range of metric values associated with each tier monotonically increases with the position of the tier in the ordering.
5. The method of claim 3 , wherein the respective subsets of the set of document identification tags associated with each tier monotonically increase with the position of the tier in the ordering; and wherein the respective predetermined range of metric values associated with each tier monotonically increases with the position of the tier in the ordering. 8. The method of claim 5 , wherein the query-independent metric is a PageRank of the new document.