Language Processing for Spoken Dialogue Systems: Is Shallow Parsing Enough?

With maturing speech technology, spoken dialogue systems are increasingly moving from research prototypes to fielded systems. The fielded systems however generally employ much simpler linguistic and dialogue processing strategies than the research prototypes. We describe an implemented spoken-language dialogue system for a travel planning domain which supports a mixed initiative dialogue strategy. The system accesses a commercially available travel information web-server. The system architecture combines both shallow and deep linguistic processors, partly so that a robust if shallow analysis is always available to the dialogue manager, and partly so that we can begin to examine where significant gains can be made by employing more advanced linguistic processing. We present the results of a preliminary investigation using data from a Wizard of Oz experiment. The results lend limited support to our original hypothesis that deep linguistic processing will prove useful at points where the user takes the initiative in driving the dialogue forward.