Some Statistical Methods Applicable to Key Comparisons Studies
Hariharan K. Iyer, Chih-Ming Wang, Dominic F. Vecchia
Results of International Key Comparisons of National Measurement Standards provide the technical basis for the Mutual Recognition Arrangement formulated by Le Comite International des Poids et Mesures. With many key comparisons already completed and a number of new key comparison experiments currently under way, we now have a better understanding of the statistical issues that need to be addressed for successfully analyzing key comparisons data and making proper interpretations of the results. There is clearly a need for a systematic approach for statistical analyses of key comparisons data that can be routinely implemented by all participating laboratories. In this paper we review a number of questions that arise in the context of statistical modeling and analysis of international key comparisons data and propose a systematic approach for answering these questions. The proposed approach is illustrated using real data from key comparison experiments.