8. A system comprising: a processor configured to perform speech recognition; and a computer-readable storage medium having instructions stored which, when executed by the processor, cause the processor to perform operations comprising: at a turn in a dialog between a user and a spoken dialog system: nominating a set of dialog actions and a set of contextual features, wherein the processor uses a partially observable Markov decision process in parallel with a conventional dialog state to perform the nominating; and generating an audible response in the dialog based on the set of contextual features, via a machine learning algorithm, from the set of dialog actions.
8. A system comprising: a processor configured to perform speech recognition; and a computer-readable storage medium having instructions stored which, when executed by the processor, cause the processor to perform operations comprising: at a turn in a dialog between a user and a spoken dialog system: nominating a set of dialog actions and a set of contextual features, wherein the processor uses a partially observable Markov decision process in parallel with a conventional dialog state to perform the nominating; and generating an audible response in the dialog based on the set of contextual features, via a machine learning algorithm, from the set of dialog actions. 11. The system of claim 8 , the computer-readable storage medium having additional instructions stored which, when executed by the processor, cause the processor to perform operations comprising: assigning a reward to the set of dialog actions as part of the machine learning algorithm.