A statistical evaluation of the Youden Matched-Pairs Procedure

AOAC INTERNATIONAL currently permits investigators to use the Youden Matched-Pairs Procedure to obtain estimates of the method performance indicators repeatability and reproducibility (s(r) and s(R), respectively). This report explains the statistical model assumptions upon which the procedure is based, provides validity tests for several of these assumptions, explains conditions under which Youdens' "precision error" is not consistent with precision estimate Sr Or SR as defined by AQAC INTERNATIONAL, and indicates when precision estimates based on the procedure should be interpreted with caution or should not be used.