LightTag: Text Annotation Platform Tal Perry author 2021-11 text Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing: System Demonstrations Heike Adel editor Shuming Shi editor Association for Computational Linguistics Online and Punta Cana, Dominican Republic conference publication perry-2021-lighttag 10.18653/v1/2021.emnlp-demo.3 https://aclanthology.org/2021.emnlp-demo.3/ 2021-11 20 27