1. A computer-implemented method executed by one or more computing devices for building a dynamic classification dictionary, the method comprising: assigning, by at least one of the one or more computing devices, one or more sets of taxonomic nouns based upon at least one of: author-generated classification information regarding a document; a user-generated tag characterizing a portion of the document; and a method of access through which the document has been accessed; aggregating, by at least one of the one or more computing devices, the one or more sets of taxonomic nouns into a composite set of taxonomic nouns; and building, by at least one of the one or more computing devices, a dynamic classification dictionary based on the composite set of taxonomic nouns.