Xiaodong Liu, Yelong Shen, Kevin Duh, Jianfeng Gao
We propose a simple yet robust stochastic answer network (SAN) that simulates multi-step reasoning in machine reading comprehension. Compared to previous work such as ReasoNet which used reinforcement learning to determine the number of steps, the unique feature is the use of a kind of stochastic prediction dropout on the answer module (final layer) of the neural network during the training. We show that this simple trick improves robustness and achieves results competitive to the state-of-the-art on the Stanford Question Answering Dataset (SQuAD), the Adversarial SQuAD, and the Microsoft MAchine Reading COmprehension Dataset (MS MARCO).
| Task | Dataset | Metric | Value | Model |
|---|---|---|---|---|
| Question Answering | SQuAD1.1 dev | EM | 76.235 | SAN (single) |
| Question Answering | SQuAD1.1 dev | F1 | 84.056 | SAN (single) |
| Question Answering | SQuAD1.1 | EM | 79.608 | SAN (ensemble model) |
| Question Answering | SQuAD1.1 | F1 | 86.496 | SAN (ensemble model) |
| Question Answering | SQuAD1.1 | EM | 76.828 | SAN (single model) |
| Question Answering | SQuAD1.1 | F1 | 84.396 | SAN (single model) |
| Question Answering | SQuAD2.0 | EM | 71.316 | SAN (ensemble model) |
| Question Answering | SQuAD2.0 | F1 | 73.704 | SAN (ensemble model) |
| Question Answering | SQuAD2.0 | EM | 68.653 | SAN (single model) |
| Question Answering | SQuAD2.0 | F1 | 71.439 | SAN (single model) |