On quantifying the bipolarity and axis of the Farnsworth-Munsell 100-Hue test

A simple method is introduced for analyzing error score distributions from the Farnsworth-Munsell 100-Hue test. The method involves fitting a sine wave directly to the error distribution, and produces estimates of three parameters that characterize the severity of the defect, the degree of bipolarity, and the orientation of the axis of bipolarity, if one is present. The method produces good estimates of the orientation of the axes for congenital defects. It is also amenable to statistical analysis.