Unsupervised Discovery of Negative Categories in Lexicon Bootstrapping Tara McIntosh author 2010-10 text Proceedings of the 2010 Conference on Empirical Methods in Natural Language Processing Hang Li editor Lluís Màrquez editor Association for Computational Linguistics Cambridge, MA conference publication mcintosh-2010-unsupervised https://aclanthology.org/D10-1035/ 2010-10 356 365