1. A computer-implemented method executed by one or more computing devices for characterizing a document, the method comprising: determining, by at least one of the one or more computing devices, a composite set of taxonomic nouns that represent a document, by a method comprising: preparing one or more of a set of first taxonomic nouns, a set of second taxonomic nouns, a set of third taxonomic nouns, and a set of fourth taxonomic nouns by: analyzing, by at least one of the one or more computing devices, author-generated classification information regarding a document and assigning the set of first taxonomic nouns to characterize the document based upon the author-generated classification information; examining, by at least one of the one or more computing devices, a user-generated tag from a client computer characterizing a portion of the document and assigning the set of second taxonomic nouns to characterize the document based upon the user-generated tag characterization; identifying, by at least one of the one or more computing devices, a method of access through which the document has been accessed from a content provider and assigning the set of third taxonomic nouns to characterize the document based upon the search term; and evaluating, by at least one of the one or more computing devices, attributes related to the method of access and assigning the set of fourth taxonomic nouns to characterize the document based upon the attributes related to the method of access; preparing, by at least one of the one or more computing devices, a set of fifth taxonomic nouns by processing the document based upon a predetermined pattern rule; and aggregating, by at least one of the one or more computing devices, at least one of the one or more prepared sets of taxonomic nouns with the set of fifth taxonomic nouns into the composite set of taxonomic nouns; and characterizing, by at least one of the one or more computing devices, the document based on the composite set of taxonomic nouns.