Dataset and Neural Recurrent Sequence Labeling Model for Open Domain Factoid Question Answering
While question answering (QA) with neural network, i.e. neural QA, has achieved promising results in recent years, lacking of large scale real word QA dataset is still a challenge for developing and evaluating neural QA system. To alleviate this problem, we propose a large scale human annotated real world QA dataset WebQA with more than 42k questions and 556k evidences. As existing neural QA methods resolve QA either as sequence generation or classification/ranking problem, they face challenges of expensive softmax computation, unseen answers handling or separate candidate answer generation component. In this work, we cast neural QA as a sequence labeling problem and propose an end to end sequence labeling model, which overcomes all the above challenges. Experimental results on WebQA show that our model outperforms the baselines significantly with an F1 score of 74.69% with word based input, and the performance drops only 3.72 F1 points with more challenging character based input.
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