Fraction of positives for each one of the classes as a function of the mean predicted probability. The ECE for galaxies, QSO-h, QSO-l, stars, and the mean ECE are shown at the top left side of each panel. The error bar represents the standard deviation in each one of the bins. The left panels are trained with the original training set, and the right panel used the hybrid set. The top (bottom) panels show the results of ANN₁ (ANN₂).