INVITED TALK 1: The Knowledge Base Population Task: Challenges for Information Extraction Ralph Grishman author 2011-09 text Proceedings of the RANLP 2011 Workshop on Information Extraction and Knowledge Acquisition Preslav Nakov editor Zornitsa Kozareva editor Kuzman Ganchev editor Jerry Hobbs editor Association for Computational Linguistics Hissar, Bulgaria conference publication grishman-2011-invited https://aclanthology.org/W11-4001/ 2011-09 1