We investigated the dependence between retention of five different test solutes and the mobile phase composition in thin-layer chromatographic systems with the chemically bonded 3-cyanopropyl stationary phase and binary 2-propanol - n-hexane eluents. Then, we calculated regression parameters for the selected three models of solute retention (applicable to the adsorption liquid chromatography mode), first upon all 36 experimental data points and, then, upon a restricted number of four experimental data points. Finally, the relevant conclusions were drawn regarding efficiency of the retention models considered in predicting solute retention (and consequently, in optimization of separation selectivity) based upon the results of an absolutely minimal introductory experiment.