2. The computer storage media of claim 1 , wherein the lower level classes comprises a plurality of parent and/or child classes associated with the single root class.
2. The computer storage media of claim 1 , wherein the lower level classes comprises a plurality of parent and/or child classes associated with the single root class. 3. The computer storage media of claim 2 , wherein a stop feature list is stored in association with the single root class, and wherein the method further comprises: comparing the one or more features parsed from the text associated with each document to the stop feature list; and if a feature of the one or more features occurs in the stop feature list, removing the feature.