Comparison of naïve and expert subjects in the assessment of small color differences.

Determination of the role of subject experience in the development of accurate color difference formulas is of potentially critical concern. As part of a larger multivariable experiment investigating the minimum inter- and intra-subject variability possible among a set of subjects, a study was conducted to compare the performance of 25 novice versus 25 expert visual assessors for a set of 27 pairs of colored textile samples using a controlled psychophysical method and several statistical techniques including t-test, ANOVA, and Standardized Residual Sum of Squares (STRESS) functions. Experts exhibited approximately 43% higher visual difference ratings than novice subjects when assessing sample pairs having small color differences. In addition, a statistically significant difference at the 95% confidence level was found between the judgments made by novice and expert assessors. According to the STRESS function, however, CMC(1:1) and CIEDE2000(1:1) color difference formulas do not show a significant difference in performance when the visual data from either group of subjects are compared.