Difference between the score obtained with the ANN₁ trained in the original training set and the reduced set (ten times smaller), the hybrid set (five time larger), the reduced hybrid set ×5 (five times larger than the reduced set), and the reduced hybrid set ×10 (ten times larger than the reduced set) as a function of the median S/N. Dashed vertical lines indicate an S/N of 10 and 5.