We estimate the distribution of likely DA types for a given utterance using the entire conversation E as evidence, and then use a sentence-level mixture (Iyer, Ostendorf, and Rohlicek 1994) of DA-specific LMs in a single recognizer run.
we replace P(WilUi) in Equation 11 with ~_~ P(WilUi)P(Ui]E), ui a weighted mixture of all DA-specific LMs.