Conversation Trees: A Grammar Model for Topic Structure in Forums Annie Louis author Shay B Cohen author 2015-09 text Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing Lluís Màrquez editor Chris Callison-Burch editor Jian Su editor Association for Computational Linguistics Lisbon, Portugal conference publication louis-cohen-2015-conversation 10.18653/v1/D15-1178 https://aclanthology.org/D15-1178/ 2015-09 1543 1553