Two-dimensional density distribution of the residual between trained CNN labels and APOGEE input labels as a function of the APOGEE input labels for the training sample (44780 stars, left column). The black dashed line shows a null difference. The mean bias (b) and dispersion (σ) of the difference is given in the bottom-left corner of the panels. Each panel also contains a histogram of the input label. The right panels show differences between the calibrated GSP-Spec parameters (with good quality flags; Recio-Blanco et al. 2023) and APOGEE labels.