Look at Data to Evaluate Uncertainty: A comment on "Uranium Assay Determination...." by Mathew et al.
Ryan P. Fitzgerald
According to the Guide to the Expression of Uncertainty in Measurement (GUM), the evaluation of uncertainty should be based as much as possible on observed data. In a recent paper, Mathew et al. detailed, for a specific titration-based assay of uranium, a step-by-step approach to calculate the GUM uncertainty of the measurand , which was based solely on prior knowledge, ignoring the manifest variability of the data. A better uncertainty evaluation is possible, and is heirin demonstrated, without even the inclusion of correction factors, but by simply extracting as much knowledge as possible from the extant data. This knowledge could then be fed back into the planning of further experimental work.