Human experts write summaries using different techniques, including rewriting a sentence in the document or fusing multiple sentences to generate a summary sentence. These techniques are flexible and thus difficult to be imitated by any single method. To address this issue, we propose an adaptive model, GEMINI, that integrates a rewriter and a fuser to mimic the sentence rewriting and fusion techniques, respectively. GEMINI adaptively chooses to rewrite a specific document sentence or generate a summary sentence from scratch. Experiments demonstrate that our adaptive approach outperforms the pure abstractive and rewriting baselines on various benchmark datasets, especially when the dataset has a balanced distribution of styles. Interestingly, empirical results show that the human writing style of each summary sentence is consistently predictable given its context.

翻译：人类专家在撰写摘要时会运用多种技巧，包括改写文档中的句子或将多个句子融合生成摘要句。这些技巧灵活多变，难以通过单一方法模仿。为解决此问题，我们提出自适应模型GEMINI，该模型整合了改写器与融合器，分别模拟句子改写与融合技术。GEMINI能自适应地选择改写特定文档句子或从头生成摘要句。实验表明，在多个基准数据集上，我们的自适应方法优于纯抽象式和改写基线方法，尤其当数据集的风格分布均衡时表现更佳。有趣的是，实证结果显示，每个摘要句的人类写作风格在其上下文中始终具有可预测性。