Towards Zero-Shot Conditional Summarization with Adaptive Multi-Task Fine-Tuning.

Automatic summarization research has traditionally focused on providing high quality general-purpose summaries of documents. However, there are many applications that require more specific summaries, such as supporting question answering or topic-based literature discovery. In this paper, we study the problem of conditional summarization in which content selection and surface realization are explicitly conditioned on an ad-hoc natural language question or topic description. Because of the difficulty in obtaining sufficient reference summaries to support arbitrary conditional summarization, we explore the use of multi-task fine-tuning (MTFT) on twenty-one natural language tasks to enable zero-shot conditional summarization on five tasks. We present four new summarization datasets, two novel "online" or adaptive task-mixing strategies, and report zero-shot performance using T5 and BART, demonstrating that MTFT can improve zero-shot summarization quality.