Resistivity data should be edited before the inversion because resistivity data are contaminated by a lot of noise. Generally, outlier or data violating pants-leg effect in dipole-dipole array were used to be rejected in the apparent resistivity pseudo-section. For more precise data editing, normalized voltage curves are used. In this study, we analyzed the behavior of normalized voltage curves for pole-pole, pole-dipole and dipole-dipole arrays in the presence of threedimensional inhomogeneities, and finally re-examined the validity of normalized voltage curves in the editing process of resistivity data.