A comparison has been attempted between modelling and experimental results for localized corrosion situations. Impedance models have been discussed in order to exhibit some schematic behaviours in relation to the basic concepts of localized corrosion situations. Two aspects of the impedance of the corroded area have been more precisely investigated: its ohmic contribution and its dependence on its spatial location. The influence of the main feature of the localized corrosion situations, the electrical coupling between the passive and the corroded areas, on the impedance response of the whole electrode has been demonstrated.