Difficulty-aware Distractor Generation for Gap-Fill Items Chak Yan Yeung author John Lee author Benjamin Tsou author 2019-4–6 dec text Proceedings of the 17th Annual Workshop of the Australasian Language Technology Association Meladel Mistica editor Massimo Piccardi editor Andrew MacKinlay editor Australasian Language Technology Association Sydney, Australia conference publication yeung-etal-2019-difficulty https://aclanthology.org/U19-1021/ 2019-4–6 dec 159 164