Bidirectional Encoder Representations from Transformers (BERT) represents the latest incarnation of pretrained language models which have recently advanced a wide range of natural language processing tasks. In this paper, we showcase how BERT can be usefully applied in text summarization and propose a general framework for both extractive and abstractive models. We introduce a novel document-level encoder based on BERT which is able to express the semantics of a document and obtain representations for its sentences. Our extractive model is built on top of this encoder by stacking several inter-sentence Transformer layers. For abstractive summarization, we propose a new fine-tuning schedule which adopts different optimizers for the encoder and the decoder as a means of alleviating the mismatch between the two (the former is pretrained while the latter is not). We also demonstrate that a two-staged fine-tuning approach can further boost the quality of the generated summaries. Experiments on three datasets show that our model achieves state-of-the-art results across the board in both extractive and abstractive settings. Our code is available at https://github.com/nlpyang/PreSumm

本研究展示了BERT如何在文本摘要中有用地应用，并提出了一种通用的框架，包括抽取式模型和生成式模型。在此框架下，我们引入了一种新的基于BERT的文档级编码器，该编码器能够表达文档的语义并获取其句子的表示，通过堆叠多个Transformer层来构建我们的抽取式模型，对于生成式摘要，我们提出一种新的微调策略，以解决编码器和解码器之间的不匹配问题，并演示了两阶段微调方法可以进一步提高生成摘要的质量。在三个数据集上的实验表明，我们的模型不仅在抽取式设置下，在生成式设置下也达到了最先进的水平。

使用预训练编码器进行文本摘要