Despite the progress made in sentence-level NMT, current systems still fall
short at achieving fluent, good quality translation for a full document. Recent
works in context-aware NMT consider only a few previous sentences as context
and may not scale to entire documents. To this end, we propose a novel and
scalable top-down approach to hierarchical attention for context-aware NMT
which uses sparse attention to selectively focus on relevant sentences in the
document context and then attends to key words in those sentences. We also
propose single-level attention approaches based on sentence or word-level
information in the context. The document-level context representation, produced
from these attention modules, is integrated into the encoder or decoder of the
Transformer model depending on whether we use monolingual or bilingual context.
Our experiments and evaluation on English-German datasets in different document
MT settings show that our selective attention approach not only significantly
outperforms context-agnostic baselines but also surpasses context-aware
baselines in most cases.

提出了基于上下文感知 NMT 的层次化注意力机制来处理整个文档的翻译，并使用稀疏注意力机制在文档上选择性地关注相关句子和关键词，将这些注意力模块产生的文档级上下文表示集成到 Transformer 模型的编码器或解码器中，通过在英德数据集上的实验进一步验证了该方法的有效性。