7. The method of claim 1 , further comprising receiving, during the dialog, disambiguating information from a user, wherein applying the disambiguating information removes dialog actions from the set of allowed dialog actions.
1. A method comprising: at each turn in a dialog, nominating via a processor, using a partially observable Markov decision process in parallel with a conventional dialog state, a set of allowed dialog actions and a set of contextual features; and generating a response based on the set of contextual features and a dialog action selected, via a machine learning algorithm, from the set of allowed dialog actions.