Improving Domain Generalization with Domain Relations

Distribution shift presents a significant challenge in machine learning, where models often underperform during the test stage when faced with a different distribution than the one they were trained on. This paper focuses on ___domain shifts, which occur when the model is applied to new domains that are different from the ones it was trained on, and propose a new approach called D^3G. Unlike previous methods that aim to learn a single model that is ___domain invariant, D^3G leverages ___domain similarities based on ___domain metadata to learn ___domain-specific models. Concretely, D^3G learns a set of training-___domain-specific functions during the training stage and reweights them based on ___domain relations during the test stage. These ___domain relations can be directly obtained and learned from ___domain metadata. Under mild assumptions, we theoretically prove that using ___domain relations to reweight training-___domain-specific functions achieves stronger out-of-___domain generalization compared to the conventional averaging approach. Empirically, we evaluate the effectiveness of D^3G using real-world datasets for tasks such as temperature regression, land use classification, and molecule-protein binding affinity prediction. Our results show that D^3G consistently outperforms state-of-the-art methods.