The World Wide Web currently has a huge amount of data, with practically no classification information, and this makes it extremely difficult to handle effectively. It has been realized recently that the only feasible way to radically improve the situation is to add to Web objects a metadata classification, to help search engines and Web-based digital libraries to properly classify and structure the information present in the WWW. However, having a few standard metadata sets is insufficient in order to have a fully classified World Wide Web. The first major problem is that it will take some time before a reasonable number of people start using metadata to provide a better Web classification. The second major problem is that no one can guarantee that a majority of the Web objects will be ever properly classified via metadata. In this paper, we address the problem of how to cope with such intrinsic limits of Web metadata, proposing a method that is able to partially solve the above two ...