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.