22. The media of claim 20 , wherein execution of the instructions dynamically selects the set of predictions including generating ranked predictions by ordering the plurality of predictions according to descending probability.
20. A physical, non-transitory computer readable media including executable instructions which, when executed in a processor-based dialog system, classify an utterance by: receiving, in a classifier circuit of the processor-based dialog system, the utterance; generating, in a decision circuit of the processor-based dialog system, a plurality of predictions on a dialog act corresponding to the utterance; generating a plurality of probabilities each of which corresponds to a prediction; dynamically selecting a set of predictions from the plurality of predictions; and classifying, in a classifier circuit of the processor-based dialog system, the utterance according to an accumulated probability of the set of predictions, wherein the accumulated probability is an accumulated probability of variable n-best outputs, wherein the value n is a non-fixed integer value that is determined dynamically based on a classifier distribution of the utterance; and quantifying, in a performance measurement circuit coupled to the decision circuit, the performance of the decision circuit in classifying the utterance by deriving a Receiver Operating Curve (ROC) that graphs a false positive rate and a true positive rate, by varying the threshold, and calculating an area defined by the ROC.