2008 Volume 20 Issue 5 Pages 732-756
A natural language dialogue system should correctly interpret input sentences from the users and extract information essential for proper response. Since a variety of surface dependency structures may carry the same meaning, a natural language dialog system should be able to interpret such variety of expressions. Traditional semantic representations, however, take over the variety of surface dependency structures without interpreting them. Consequently, we cannot compare semantic expressions with different dependency structure. In addition, it is practically impossible to prepare interpreting rules particular to each possible input. In our previous studies, we proposed a framework for semantic representations which circumvents the problem. The framework enables us to compare semantic representations with different dependency structures without employing structure-specific rules. In this paper, we describe how to interpret a clause based on its semantic representation and show that the interpreting processes are applicable to the interpretation of multiple clauses and/or multiple sentences. We have constructed a dialogue system based on this framework and evaluated the system. As a result, we have confirmed that the system can make proper response and that the framework gives the system capacity to make proper response, as desired.