Handling time recognition for for friendly natural language interface: a case study about using temporal adverbs in Japanese

A formal method to determine the style of sentences is proposed. Sentences generated by a human are expressed in various ways, depending on his state of mind, even if he utters the same thoughts. Selecting one of the adverbs which is suitable for a situation is one of these problems. Especially in Japanese, what a speaker wants to tell a hearer is sometimes determined only by the kind of adverb. If natural language interfaces were to have the ability to handle styles of sentences or adverbs so as to adapt to a situation, they would become friendly interfaces, because they must surely understand the intention of user. In this paper, we describe the nature of the problem and propose the formalization of sentence expression by using modal logic with temporal information, then we evaluate it by comparing sentences generated by a human and by the system. As a result, it was found that the system could generate sentences which are the same as the human did. Intuitively understandable sentences for friendly natural language interfaces have thus been generated by considering information about the human mind