Label-Efficient Group Robustness via Out-of-Distribution Concept Curation

Deep neural networks are prone to capture correlations between spurious attributes and class labels, leading to low accuracy on some combinations of class labels and spurious attribute values. When a spurious attribute represents a protected class, these low-accuracy groups can manifest discriminatory bias. Existing methods attempting to improve worst-group accuracy assume the training data, validation data, or both are reliably labeled by the spurious attribute. But a model may be perceived to be biased towards a concept that is not represented by pre-existing labels on the training data. In these situations, the spurious attribute must be defined with external information. We propose Concept Correction, a framework that represents a concept as a curated set of images from any source, then labels each training sample by its similarity to the concept set to control spurious correlations. For example, concept sets representing gender can be used to measure and control gender bias even without explicit labels. We demonstrate and evaluate an instance of the framework as Concept DRO, which uses concept sets to estimate group labels, then uses these labels to train with a state of the art distributively robust optimization objective. We show that Concept DRO outperforms existing methods that do not require labels of spurious attributes by up to 33.1% on three image classification datasets and is competitive with the best methods that assume access to labels. We consider how the size and quality of the concept set influences performance and find that even smaller, manually curated sets of noisy AI-generated images are effective at controlling spurious correlations, suggesting that high-quality, reusable concept sets are easy to create and effective in reducing bias.