For interest I asked Charlotte to send this page to her classifier - the reults can be seen in the head section of this document if you view the source. Exactly the right paper at the right time. Tuple is an attribute value pair . Web cache works well for static pages but you need semantic cache for dynamic stuff. A region is a group of semantically related stuff.
Query is answered partly by stuff from cache and partly from servers.
Many things unclear to me about this stuff. Grouper clustering search results Oren Zamir and Oren Etzioni Clusters hits from search engines into groups. Clustering happens at search time not indexing time. Clustering happens only on the set retrieved. The hits are sorted by commonly occurring terms and presented to the users in this grouped form.