14. The machine readable storage of claim 13 , wherein the code for assigning the unigrams that are individually meaningless comprises code for categorizing the unigrams into at least one class selected from the group consisting of a nonsensical class and at least one ambiguous class.
15. The machine readable storage of claim 14 , wherein the code for assigning at least a portion of the unigrams comprises code for assigning unigrams that are categorized as nonsensical into the first n-gram class and assigning unigrams that are categorized as ambiguous into at least a second n-gram class selected from the plurality of n-gram classes.