In this short note we demonstrate the applicability of hyperlink downweighting by means of language model disagreement. The method filters out hyperlinks with no relevance to the target page without the need of white and blacklists or human interaction. We fight various forms of nepotism such as common maintainers, ads, link exchanges or misused affiliate programs. Our method is tested on a 31 M page crawl of the .de domain with a manually classified 1000-page random sample.

Personalized PageRank expresses link-based page quality around user selected pages. The only previous personalized PageRank algorithm that can serve on-line queries for an unrestricted choice of pages on large graphs is our Monte Carlo algorithm [WAW 2004]. In this paper we achieve unrestricted personalization by combining rounding and randomized sketching techniques in the dynamic programming algorithm of Jeh and Widom [WWW 2003]. We evaluate the precision of approximation experimentally on large scale real-world data and find significant improvement over previous results. As a key theoretical contribution we show that our algorithms use an optimal amount of space by also improving earlier asymptotic worst-case lower bounds. Our lower bounds and algorithms apply to the SimRank as well; of independent interest is the reduction of the SimRank computation to personalized PageRank.