A Non-negative Matrix Factorization Based Approach for Active Dual Supervision from Document and Word Labels Chao Shen author Tao Li author 2011-07 text Proceedings of the 2011 Conference on Empirical Methods in Natural Language Processing Regina Barzilay editor Mark Johnson editor Association for Computational Linguistics Edinburgh, Scotland, UK. conference publication shen-li-2011-non https://aclanthology.org/D11-1088/ 2011-07 949 958