AStarTwice at SemEval-2021 Task 5: Toxic Span Detection Using RoBERTa-CRF, Domain Specific Pre-Training and Self-Training Thakur Ashutosh Suman author Abhinav Jain author 2021-08 text Proceedings of the 15th International Workshop on Semantic Evaluation (SemEval-2021) Alexis Palmer editor Nathan Schneider editor Natalie Schluter editor Guy Emerson editor Aurelie Herbelot editor Xiaodan Zhu editor Association for Computational Linguistics Online conference publication suman-jain-2021-astartwice 10.18653/v1/2021.semeval-1.118 https://aclanthology.org/2021.semeval-1.118/ 2021-08 875 880