Difficulty Indices for the Named Entity Task in Japanese Chikashi Nobata author Satoshi Sekine author Jun’ichi Tsujii author 2000-10 text Proceedings of the 38th Annual Meeting of the Association for Computational Linguistics Association for Computational Linguistics Hong Kong conference publication nobata-etal-2000-difficulty 10.3115/1075218.1075262 https://aclanthology.org/P00-1044/ 2000-10 344 351