6. The call center device of claim 1 further comprising: a training device comprising at least one computer configured to construct the set of word lattices from training dialogs between call center agents and second parties and to assign to the word lattices τ the conditional probabilities p(τ|DA type) over dialog act types DA type.
6. The call center device of claim 1 further comprising: a training device comprising at least one computer configured to construct the set of word lattices from training dialogs between call center agents and second parties and to assign to the word lattices τ the conditional probabilities p(τ|DA type) over dialog act types DA type. 14. The call center device of claim 6 wherein the training device is configured to assign to the word lattices τ the conditional probabilities p(τ|DA type) by operations that for each word lattice τ include: sampling the word lattice τ to generate sample utterances; labeling each sample utterance with conditional probabilities p(DA type|utt) where utt is the sample utterance and DA type is a dialog act type; and generating the conditional probabilities p(τ|DA type) for the word lattice τ from the conditional probabilities p(DA type|utt) of the sample utterances.