Measuring Online Debaters’ Persuasive Skill from Text over Time Kelvin Luu author Chenhao Tan author Noah A Smith author 2019 text journal article Transactions of the Association for Computational Linguistics continuing MIT Press Cambridge, MA periodical academic journal luu-etal-2019-measuring 10.1162/tacl_a_00281 https://aclanthology.org/Q19-1031/ 2019 7 537 550