Perturbed Model Validation: A New Framework to Validate Model Relevance

This paper introduces PMV (Perturbed Model Validation), a new technique to validate model relevance and detect overfitting or underfitting. PMV operates by injecting noise to the training data, re-training the model against the perturbed data, then using the training accuracy decrease rate to assess model relevance. A larger decrease rate indicates better concept-hypothesis fit. We realise PMV by using label flipping to inject noise, and evaluate it on four real-world datasets (breast cancer, adult, connect-4, and MNIST) and three synthetic datasets in the binary classification setting. The results reveal that PMV selects models more precisely and in a more stable way than cross-validation, and effectively detects both overfitting and underfitting.