Bayesian Approaches to Calculating a Reference Value in Key Comparison Experiments

International experiments called key comparisons pose an interesting statistical problem: estimation of a quantity called a reference value. This estimator can take many possible forms; so far, none has been accepted as a standard. Recently, this topic has received much international attention. In this article it is argued that a fully Bayesian approach to this problem is compatible with the current practice of metrology and can be used to create models for the varied properties and assumptions of these experiments.