A Note On "A Concordance Correlation Coefficient to Evaluate Reproducibility"

Lin (1989, Biometrics 45, 255-268) objected to the use of the intraclass correlation coefficient as a way to evaluate the reproducibility of measurements between two trials of an assay or instrunent and developed an alternative called the concordance correlation coefficient. It is noted that intraclass correlation refers not to a single coefficient but to a group of coefficients and that Lin's alternative is nearly identical to a subset of the coefficients in this group.