12. The method of claim 9 , wherein the generating of the message comprises: for each lexical slot in the plurality of lexical slots: accessing the corpus of source data corresponding to the lexical slot; selecting a term from the corpus of source data in accordance with the grammatical constraint corresponding to the lexical slot; and populating the lexical slot with the selected term.
13. The method of claim 12 , wherein the grammatical constraint specifies a lexical category, and wherein the selected term corresponds to the lexical category.