7. A spoken dialogue interface method implemented by a spoken dialogue interface apparatus comprising a processor having computing device-executable instructions, the method comprising the steps of: recognizing a human's speech from a sound signal in a speech recognition module; extracting a sentence from the recognized speech and interpreting the user's intention based on the sentence; determining the user intention using the interpreted user's intention and selecting a first predetermined domain action frame from a plurality of predetermined domain action frames in a user intention selection module; generating a system response sentence corresponding to the determined user intention and the selected first domain action frame in a system response generation module, wherein the first domain action frame includes service information which the user requests, and parameter information which is used to perform a service, and the first domain action frame is one of the plurality of domain action frames represented as nodes in a hierarchical tree structure; and generating, by way of the processor, the system response sentence with reference to a second domain action frame when a corresponding system response sentence does not exist in the first domain action frame due to missing of some parameter information with respect to the first domain action frame, the second domain action frame being a service provided by a predetermined domain represented as a node in the hierarchical tree structure and existing in an upper layer of the hierarchical tree structure in a back-off response model storage module.
7. A spoken dialogue interface method implemented by a spoken dialogue interface apparatus comprising a processor having computing device-executable instructions, the method comprising the steps of: recognizing a human's speech from a sound signal in a speech recognition module; extracting a sentence from the recognized speech and interpreting the user's intention based on the sentence; determining the user intention using the interpreted user's intention and selecting a first predetermined domain action frame from a plurality of predetermined domain action frames in a user intention selection module; generating a system response sentence corresponding to the determined user intention and the selected first domain action frame in a system response generation module, wherein the first domain action frame includes service information which the user requests, and parameter information which is used to perform a service, and the first domain action frame is one of the plurality of domain action frames represented as nodes in a hierarchical tree structure; and generating, by way of the processor, the system response sentence with reference to a second domain action frame when a corresponding system response sentence does not exist in the first domain action frame due to missing of some parameter information with respect to the first domain action frame, the second domain action frame being a service provided by a predetermined domain represented as a node in the hierarchical tree structure and existing in an upper layer of the hierarchical tree structure in a back-off response model storage module. 8. The spoken dialogue interface method as set forth in claim 7 , wherein the system response sentence is set in the first or second domain action frame.