This UMIST 0.6 m diameter column has been used with 3 systems-methanol-water, isopropanol-water and toluene-methylcyclohexane-to generate point efficiency data. These data have been compared with the predictions of a number of published methods, to provide evidence of their accuracy and guidance in their use. The methods of Stichlmair, and of Chan and Fair proved most accurate, confirming the conclusions of a recent publication by Dribika and Biddulph. For the data measured here the Hughmark method provided similar accuracy. Expected accuracy of prediction-about +/- 10% absolute.