Social Media Text Classification under Negative Covariate Shift Geli Fei author Bing Liu author 2015-09 text Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing Lluís Màrquez editor Chris Callison-Burch editor Jian Su editor Association for Computational Linguistics Lisbon, Portugal conference publication fei-liu-2015-social 10.18653/v1/D15-1282 https://aclanthology.org/D15-1282/ 2015-09 2347 2356