Factor transformation to produce statistics describing the uncertainty of analytical data

Analytical uncertainty produced by random error has a positively skewed dis tribution and accuracy and precision have non-linear scales. Compared with conventional statistics, factor transformation of the data allows more appr opriate interpretation of results and facilitates graphical inspection of d ata. Statistics are compared for practical examples of performance in profi ciency tests and of repeatability and reproducibility in collaborative stud ies. Factor transformation is shown to be applicable to wide ranges of anal yte concentration and measurement precision.