Type-II dialogue systems for information access from unstructured knowledge sources

In this paper, we present a new formulation and a new framework for a new type of dialogue system, referred to as the type-II dialogue systems in this paper. The distinct feature of such dialogue systems is their tasks of information access from unstructured knowledge sources, or the lack of a well-organized back-end database offering the information for the user. Typical example tasks of this type of dialogue systems include retrieval, browsing and question answering. The mainstream dialogue systems with a well-organized back-end database are then referred to as type-I dialogue systems here in the paper. The functionalities of each module in such type-II dialogue systems are analyzed, presented, and compared with the respective modules in type-I dialogue systems. A preliminary type-II dialogue system recently developed in National Taiwan University is also presented at the end as a typical example.