Generating spontaneous elliptical utterance

To generate spontaneous utterances, it is important to omit some items from them appropriately. Previously, generation of elliptical utterances was discussed only from a view of whether an item in question is known or unknown in the context of dialogue. We point out that some items that are already known should not be omitted in some situation. For example, omitting too many items from utterances makes a hearer to feel that the speaker is impolite. In this paper, we propose some strategies to generate appropriate elliptical English utterances, given a politeness level. Our system can translate utterances with no ellipses into appropriate elliptical utterances using the strategies. The strategies are obtained by analysis of some dialogues, but we show that they are applicable to other dialogues