A Unified Span-Based Approach for Opinion Mining with Syntactic Constituents Qingrong Xia author Bo Zhang author Rui Wang author Zhenghua Li author Yue Zhang author Fei Huang author Luo Si author Min Zhang author 2021-06 text Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies Kristina Toutanova editor Anna Rumshisky editor Luke Zettlemoyer editor Dilek Hakkani-Tur editor Iz Beltagy editor Steven Bethard editor Ryan Cotterell editor Tanmoy Chakraborty editor Yichao Zhou editor Association for Computational Linguistics Online conference publication xia-etal-2021-unified 10.18653/v1/2021.naacl-main.144 https://aclanthology.org/2021.naacl-main.144/ 2021-06 1795 1804