Ranking Help Message Candidates Based on Robust Grammar Verification Results and Utterance History in Spoken Dialogue Systems Kazunori Komatani author Satoshi Ikeda author Yuichiro Fukubayashi author Tetsuya Ogata author Hiroshi Okuno author 2009-09 text Proceedings of the SIGDIAL 2009 Conference Patrick Healey editor Roberto Pieraccini editor Donna Byron editor Steve Young editor Matthew Purver editor Association for Computational Linguistics London, UK conference publication komatani-etal-2009-ranking https://aclanthology.org/W09-3946/ 2009-09 314 321