Testing the Equality of Two Related Intraclass Reliability Coefficients

Abstract

An approximate statistical test of the equality of two intraclass reliability coefficients based on the same sample of people is derived. Such a test is needed when a researcher wishes to compare the reliability of two measurement procedures and both procedures can be applied to the performances or products of the same group of individuals. A numerical example is presented. Monte carlo studies indicate that the proposed test effectively controls Type I error with as few as two or three measurements on each of 50 people. Index terms: equality of related intraclass reliability coefficients, intraclass reliability, sampling theory, Speannan-Brown extrapolation, statistical test.