An abstract must not change the meaning of the original text. A single most
effective way to achieve that is to increase the amount of copying while still
allowing for text abstraction. Human editors can usually exercise control over
copying, resulting in summaries that are more extractive than abstractive, or
vice versa. However, it remains poorly understood whether modern neural
abstractive summarizers can provide the same flexibility, i.e., learning from
single reference summaries to generate multiple summary hypotheses with varying
degrees of copying. In this paper, we present a neural summarization model
that, by learning from single human abstracts, can produce a broad spectrum of
summaries ranging from purely extractive to highly generative ones. We frame
the task of summarization as language modeling and exploit alternative
mechanisms to generate summary hypotheses. Our method allows for control over
copying during both training and decoding stages of a neural summarization
model. Through extensive experiments we illustrate the significance of our
proposed method on controlling the amount of verbatim copying and achieve
competitive results over strong baselines. Our analysis further reveals
interesting and unobvious facts.

通过学习自单一人类摘要信息，我们提出了一种神经网络摘要模型，该模型可以生成从纯粹提取式到高度生成式的多种摘要假设，并在控制文本复制的同时实现训练和解码阶段内的控制，从而实现了竞争性的结果。