Assessing Sample Quality in Conditional Generation under Compositional Shift
This work addresses the challenge of evaluating conditional generation quality in compositional extrapolation settings, where the true target distribution is unavailable. The authors propose a post-hoc, instance-wise confidence scoring mechanism that requires no access to the target distribution. By constructing estimable metrics based on data manifold compatibility and attribute contrastive distance, the method holistically assesses both global realism and attribute fidelity. Notably, it incurs no additional training and is directly applicable to off-the-shelf pre-trained generative models. To the best of our knowledge, this is the first approach enabling effective evaluation of compositional extrapolation samples, facilitating sample filtering, ranking, and pre-generation abstention. Experiments on biological imaging and visual benchmarks demonstrate substantial improvements in morphological fidelity and downstream predictive performance, along with the capability for early abstention during generation.