WWW2009 EPrints

User-Centric Content Freshness Metrics for Search Engines

This item is a Poster.

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In order to return relevant search results, a search engine must keep its local repository synchronized to the Web, but it is usually impossible to attain perfect freshness. Hence, it is vital for a production search engine continually to monitor and improve repository freshness. Most previous freshness metrics, formulated in the context of developing better synchronization policies, focused on the web crawler while ignoring other parts of a search engine. But, the freshness of documents in a web crawler does not necessarily translate directly into the freshness of search results as seen by users. We propose metrics for measuring freshness from a user’s perspective, which take into account the latency between when documents are crawled and when they are viewed by users, as well as the variation in user click and view frequency among different documents. We also describe a practical implementation of these metrics that were used in a production search engine.

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About this site

This website has been set up for WWW2009 by Christopher Gutteridge of the University of Southampton, using our EPrints software.


We (Southampton EPrints Project) intend to preserve the files and HTML pages of this site for many years, however we will turn it into flat files for long term preservation. This means that at some point in the months after the conference the search, metadata-export, JSON interface, OAI etc. will be disabled as we "fossilize" the site. Please plan accordingly. Feel free to ask nicely for us to keep the dynamic site online longer if there's a rally good (or cool) use for it... [this has now happened, this site is now static]