Problems with scaling of conductive-system experimental Mdat″(ω) and σdat′(ω) data are considered and resolved by dispersive-relaxation-model fitting and comparison. Scaling is attempted for both synthetic and experimental M″(ω) data sets. A crucial element in all experimental frequency-response data is the influence of the high-frequency-limiting dipolar-and-vibronic dielectric constant εD∞, often designated ε∞, and not related to ionic transport. It is shown that εD∞ precludes scaling of Mdat″(ω) for ionic materials when the mobile-charge concentration varies. When the effects of εD∞ are properly removed from the data, however, such scaling is viable. Only the σ′(ω) and ε″(ω) parts of immittance response are uninfluenced by εD∞. Thus, scaling is possible for experimental σ′(ω) data sets under concentration variation if the shape parameter of a well-fitting model remains constant and if any parts of the response not associated with bulk ionic transport are eliminated. Comparison between the predictions of the original-modulus-formalism (OMF) response model of 1972–1973 and a corrected version of it that takes proper account of εD∞, the corrected modulus formalism (CMF), demonstrates that the role played by εD∞ (or ε∞) in the OMF is incorrect. Detailed fitting of data for three different ionic glasses using a Kohlrausch–Williams–Watts response model, the KWW1, for OMF and CMF analysis clearly demonstrates that the OMF leads to inconsistent shape-parameter (β1) estimates and the CMF does not. The CMF KWW1 model is shown to subsume, correct, and generalize the recent disparate scaling/fitting approaches of Sidebottom, León, Roling, and Ngai.