Evaluation of poor performance and asymmetry in the Farnsworth-Munsell 100-hue test

A statistical method for the analysis of errors on the Farnsworth-Munsell 100-hue test is introduced. The extent of asymmetry of errors are summarized by two indices, I1 and I2, derived from Fourier analysis of the error scores for the individual caps. The second index, I2, describes the (bipolar) color axis; the first index, I1, describes (monopolar) asymmetry of performance. The present analysis differs from previous approaches based on Fourier analysis of the errors in two ways: (1) a procedure is introduced which corrects the indices I1 and I2 for the biases that result from the segmentation of the test into four boxes; (2) statistics for the significance of I1 and I2 are derived by a Monte Carlo procedure, which properly handles the complex interdependence of individual error scores for each cap.