An exhaust-gas sensor signal (vls_down) of an exhaust-gas sensor that is disposed in an exhaust gas train downstream of at least one first catalytic converter volume (V1) and upstream of at least one second catalytic converter volume (V2) is acquired. An estimated value of an intermediate emission for a position of the exhaust-gas sensor is determined in dependence upon the exhaust-gas sensor signal (vls_down). An estimated value of an emission downstream of the at least one second catalytic converter volume (V2) is determined in dependence upon the estimated value of the intermediate emission and in dependence upon at least one predefined correction characteristic (fac_cor_ufc) or at least one predefined correction characteristics map for correcting the estimated value of the intermediate emission with regard to an influence of the at least one second catalytic converter volume (V2) upon the emission of the at least one exhaust gas component.