The dielectric relaxation experimental data on the alpha- and Johari-Goldstein beta-relaxation dynamics of sorbitol in the neat state and in mixtures with glycerol published by Duvvuri and Richert (J. Phys. Chem. B, published online Apr 23, http://dx.doi.org/10.1021/jp031366b) is challenging to explain. Not only does one need a theory or model that can address both the alpha-and Johari-Goldstein beta-relaxation dynamics in a neat glassformer, but one also a theory or model that can address them in a mixture. The coupling model fulfills these requirements. Naturally, we employ the coupling model to interpret the experimental data. Fair agreements are found between the predictions of the model and data of neat sorbitol and mixtures of sorbitol with glycerol.