Comparison between the abundances based on the slit spectra of H II regions and the abundances estimated from the IFU spectra of H II regions (or spatial samplings, fibres) using the R and the S calibrations. Panel a1: IFU spectra-based oxygen abundances obtained through the S calibration vs. oxygen abundances estimated from the slit spectra for our sample of galaxies (each point shows the median value in bins of 0.1 in R/R₂₅ in individual galaxy, see Fig. 3, Figs. A.1–A.7). The abundances based on the IFU spectra from different surveys are shown by different symbols. The solid line indicates the one-to-one relation, while the dashed line shows the ±0.1 dex deviation. Panel b1: same as panel (a1) but for the IFU spectra-based abundances estimated through the R calibration. Panel a2: grey points are data from panel (a1), and the dark circles mark the mean value in bins of 0.05 in log(O/H) for those data points. Panel b2: same as panel (a2) but for the IFU spectra-based abundances estimated through the R calibration.