Less is More: Mitigate Spurious Correlations for Open-Domain Dialogue Response Generation Models by Causal Discovery Tao Feng author Lizhen Qu author Gholamreza Haffari author 2023 text journal article Transactions of the Association for Computational Linguistics continuing MIT Press Cambridge, MA periodical academic journal feng-etal-2023-less 10.1162/tacl_a_00561 https://aclanthology.org/2023.tacl-1.30/ 2023 11 511 530