In the natural language processing literature, neural networks are becoming increasingly deeper and complex. The recent poster child of this trend is the deep language representation model, which includes BERT, ELMo, and GPT. These developments have led to the conviction that previous-generation, shallower neural networks for language understanding are obsolete. In this paper, however, we demonstrate that rudimentary, lightweight neural networks can still be made competitive without architecture changes, external training data, or additional input features. We propose to distill knowledge from BERT, a state-of-the-art language representation model, into a single-layer BiLSTM, as well as its siamese counterpart for sentence-pair tasks. Across multiple datasets in paraphrasing, natural language inference, and sentiment classification, we achieve comparable results with ELMo, while using roughly 100 times fewer parameters and 15 times less inference time.

本文主要研究神经网络中的自然语言处理，通过将BERT知识蒸馏成单层BiLSTM及其同侧对应的句对任务，证明了浅层神经网络仍然可以在不使用架构变化、外部训练数据或其他输入特征的情况下，与ELMo相比获得可媲美的结果。

从BERT中提炼出特定任务的知识并转化为简单的神经网络