Learning to Generalize: Meta-Learning for Domain Generalization

Domain shift refers to the well known problem that a model trained in one source ___domain performs poorly when applied to a target ___domain with different statistics. {Domain Generalization} (DG) techniques attempt to alleviate this issue by producing models which by design generalize well to novel testing domains. We propose a novel {meta-learning} method for ___domain generalization. Rather than designing a specific model that is robust to ___domain shift as in most previous DG work, we propose a model agnostic training procedure for DG. Our algorithm simulates train/test ___domain shift during training by synthesizing virtual testing domains within each mini-batch. The meta-optimization objective requires that steps to improve training ___domain performance should also improve testing ___domain performance. This meta-learning procedure trains models with good generalization ability to novel domains. We evaluate our method and achieve state of the art results on a recent cross-___domain image classification benchmark, as well demonstrating its potential on two classic reinforcement learning tasks.