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Incoming links: Overfitting
Past exam of the mathematics course of the University of Cambridge 2026 iii Paper 218 5 d Solution Created 2026-09-24 Updated 2026-09-24
The dashed curve is training accuracy: it continues to rise as optimization adapts to the training observations. The solid curve is testing accuracy: it peaks near 10 epochs and then declines. The widening gap is overfitting.
A sensible choice is about 10 epochs, selected by early stopping at the maximum validation accuracy. In a proper analysis, a validation set rather than the final test set should choose this epoch. Early stopping is an implicit regularization method because it limits how far the parameters can adapt to training-specific noise.