The pages in a network of linked pages are ranked based on the quality of the pages. Page quality is obtained by determining the change over time of the link structure of the page, which is obtained by determining the link structure of the page at different periods of time by taking multiple snapshots of the link structure of the network. The link structures are approximated by their PageRanks, page quality being determined by the formula:
where Q(p) is the quality of the page, PR(p) is the current PageRank of the page, ΔPR(p) is the change over time in the PageRank of the page, and D is a constant that determines the relative weight of the terms ΔPR(p)/PR(p) and PR(p).