The percentage of correction as determined by the Cobb method and the Ferguson method of measurement are not comparable. The differences and discrepancies between the two methods have been demonstrated and analyzed, showing the more favorable percentage of correction obtained by the Cobb method. When follow-up studies and end results are reported in the treatment of scoliosis, the method of measurement must be considered. Although both methods have their merits we have found the Ferguson method to be accurate. We believe it can be used by many orthopaedic surgeons with minimum, if any, error. Since this method depends on all the main components of the curve, it can be rightfully termed the method of the angle of the curve. A way of measuring the displacement of the apex of the curve toward the side of convexity of the curve has also been demonstrated as a simple and accurate way of following the progression or correction of a curve.