15. A computer-readable storage device having instructions stored which, when executed by a computing device, perform operations comprising: training a spoken dialog system using task-independent call-types of a previous application; recognizing a user utterance using the spoken dialog system, to yield a recognized user utterance; determining an acceptance threshold and a rejection threshold based on an entity referenced in the recognized user utterance; classifying the recognized user utterance, to yield a classification, where the classification meets one of: the rejection threshold, the acceptance threshold, and both the rejection threshold and the acceptance threshold; when the classification meets the acceptance threshold acting according to a call-type associated with the classification; and when the classification meets the rejection threshold, transcribing the recognized user utterance and using the recognized user utterance for further training of the spoken dialog system.
15. A computer-readable storage device having instructions stored which, when executed by a computing device, perform operations comprising: training a spoken dialog system using task-independent call-types of a previous application; recognizing a user utterance using the spoken dialog system, to yield a recognized user utterance; determining an acceptance threshold and a rejection threshold based on an entity referenced in the recognized user utterance; classifying the recognized user utterance, to yield a classification, where the classification meets one of: the rejection threshold, the acceptance threshold, and both the rejection threshold and the acceptance threshold; when the classification meets the acceptance threshold acting according to a call-type associated with the classification; and when the classification meets the rejection threshold, transcribing the recognized user utterance and using the recognized user utterance for further training of the spoken dialog system. 17. The computer-readable storage device of claim 15 , wherein the spoken dialog system performs call-type classification.