How to improve estimates of imprecision.

Abstract

Authors sometimes report total imprecision as being less than within-run imprecision. This leads one to question how well the underlying statistical concepts are understood. This article explains statistical concepts relevant to imprecision studies and reviews proper use of the relevant statistical terms. Calculation of total imprecision and its components is illustrated by a numerical example. Two of the most common calculation mistakes are pointed out. Finally, we recommend improvements in experimental design that will result in more precise estimates.