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. 7. The computer storage media of claim 2 , wherein the method further comprises: determining a probability of occurrence for the vocabulary; determining whether or not there is a dominant probability of occurrence; and classifying the vocabulary into a noise class if there is no predefined class that satisfies the dominant probability threshold at within the same equivalence level of the hierarchical structure.