Reviews: Domain Generalization via Model-Agnostic Learning of Semantic Features

My main concern is that the problem of domain generalization is not very well-defined. It is necessary to explicitly specify the underlying assumption of the proposed method. "Directly generalize to target domains with unknown statistics" as mentioned in the abstract would be impossible if the target domain is very different from the training domains. In comparison, MAML has a task distribution from which the tasks (including target) are sampled. If MASF uses the same assumption, then the problem is not really domain generalization but meta-learning from multiple tasks as in MAML.