We present META-MT, a meta-learning approach to adapt Neural Machine Translation (NMT) systems in a few-shot setting. META-MT provides a new approach to make NMT models easily adaptable to many target domains with the minimal amount of in-domain data. We frame the adaptation of NMT systems as a meta-learning problem, where we learn to adapt to new unseen domains based on simulated offline meta-training domain adaptation tasks. We evaluate the proposed meta-learning strategy on ten domains with general large scale NMT systems. We show that META-MT significantly outperforms classical domain adaptation when very few in-domain examples are available. Our experiments shows that META-MT can outperform classical fine-tuning by up to 2.5 BLEU points after seeing only 4, 000 translated words (300 parallel sentences).

META-MT 提供了一种新的基于元学习的方法来适应神经机器翻译系统 (NMT)，可以使 NMT 模型很容易地适应多个领域的目标，同时需要极少量的领域数据。通过在模拟的离线元训练领域适应任务的基础上学习如何适应新的未见过的领域，我们将 NMT 系统的适应性视为元学习问题。我们在十个领域上评估了提出的元学习策略并展示了在很少的领域样例可用时，META-MT 可以显著优于经典的领域适应并且可以在只见到 4,000 个已翻译的单词 (300 对平行句子) 后比经典微调的 BLEU 指标高出多达 2.5 个点。

Few-Shot NMT 自适应元学习