Patent ID: 7941312

Claim:
A method of generating a mixed-initiative dialog to obtain information for a set of information slots in a voice dialog system capable of receiving voice inputs from a user via at least one audio input interface and providing voice prompts to the user via at least audio output interface, the method comprising computer implemented steps performed by the voice dialog system, the method comprising: using at least one computer to performs steps of: selecting a subset of slots from the set of information slots, dependent upon a set of unfilled slots for which information is to be obtained in a current dialog cycle; constructing a composite grammar dependent upon the selected subset of slots and also dependent upon pre-defined atomic grammars each associated with at least one of the selected subset of slots and upon pre-defined grammar composition rules, the pre-defined grammar composition rules specifying: at least one of prefixes and suffixes which apply to a combination of the atomic grammars, wherein a said prefix is one of mandatory and optional and a said suffix is one of mandatory and optional; and specific permutations of slots and associated atomic grammars, wherein if certain permutations of slots are not valid or not desired, they can be specified as negative rules; generating a prompt dependent upon the selected subset of slots, wherein the prompt and the composite grammar form at least part of a current dialog cycle; receiving a user response to the prompt via the at least one audio interface; comparing the response to the composite grammar; determining, dependent upon the comparing step, if the response provides relevant information for the set of unfilled slots; and filling one or more of the set of unfilled slots with said relevant information.