Post-training with Data Augmentation for Improving T5-Based Question Generator

Post-training is known to be effective for boosting the performance of a pre-trained language model. However, in the task of question generation, question generators post-trained with a well-designed training objective show poor performance without sufficient training examples. To handle this problem, this paper proposes a novel post-training for question generation which adopts a data augmentation technique to increase the number of training examples as well as post-training objectives. As post-training objectives, this paper introduces a new training objective, wh-words deletion, in addition to the well-known question infilling. Moreover, this paper employs back-translation techniques to increase the number of instances for post-training. To prove the effectiveness of the proposed method, this paper applies the post-training strategies to T5, a large-scale pre-trained language model, on SQuAD-QG. The experimental results demonstrate that the proposed post-training is helpful for enhancing the performance of answer-aware question generation.