Evaluation of a Recursive Weighting Scheme for Federated Web Search

The informative resources available on the Web are not always directly accessible and cannot therefore be crawled since access is permitted only through the adoption of appropriate services, e.g. specialized search engines. On the other hand, specialized search engines can help address the problem of heterogeneity of the informative resources due to the type of content, the structure or the media. Federated Web Search systems address the problem of searching multiple, heterogeneous, and possibly uncooperative collections. One issue of Federated Web Search is resource selection, i.e. the selection of the search engines which most likely provide documents relevant to the query. This paper reports on the experimental evaluation in Federated Web Search setting of a recursive weighting scheme for ranking informative resources in architectures that involve an arbitrary number of resource levels.