TiO2-BaO melts have been under investigation as candidate electrolytes for the electrolytic production of titanium. Transference number measurements have been made by stepped-potential chronoamperometry at two compositions: 67 mol% TiO2 (1328 < T < 1487 degreesC) and 73 mol% TiO2 (1210 < T < 1477 degreesC). A theoretical analysis of the technique, capable of distinguishing between variations in ion density and variations in net free-charge density, is presented.