web-decay - Observe the behaviour when the legitimate...

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Sic Transit Gloria Telae: Towards an Understanding of the Web's Decay Ziv Bar-Yossef et al IBM Almaden and T.J Watson Research Centers Mark Strohmaier
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Problem Motivation Determining if a link is dead is not trivial Using dead links as a decay signal is very noisy
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Estimating Proportion of Dead Pages Begin at a page Probability 1-σ of randomly walking off, probability σ of declaring success If walk to a dead page, declare failure Overall decay score of the page is chance of failing for that page
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Differences from PageRank Decay of a page can be processed in isolation Very easy to reduce a page's decay score
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Three types of dead pages Malformed URL Host does not exist Page does not exist on host
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Detecting 'soft-404s' Query a given server for a page that does not likely exist Record the server's response to the dummy request
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Unformatted text preview: Observe the behaviour when the legitimate request is sent Measure of Decay If D is the set of all dead pages Experimental Procedure First Round of Experiments 1000 pages were randomly chosen from a web crawl of two billion 475 were already dead Of 710 dead links, 207 pointed to soft-404s First Round of Experiments Decay Score versus Dead Links Second Experiment WWW Conference links Third Experiment Yahoo Leaf Nodes Final Experiment FAQs.org Conclusions and Remarks A number of tools exist for identifying dead links, but few exist for identifying decay Incorporating decay calculations into search results could be used to improve rankings Decay computations could also be used to improve crawling...
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This note was uploaded on 08/06/2008 for the course CSE 450 taught by Professor Davison during the Spring '08 term at Lehigh University .

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web-decay - Observe the behaviour when the legitimate...

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