Why Do Document-Level Polarity Classifiers Fail? Karen Martins author Pedro O.S Vaz-de-Melo author Rodrygo Santos 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 martins-etal-2021-document 10.18653/v1/2021.naacl-main.143 https://aclanthology.org/2021.naacl-main.143/ 2021-06 1782 1794