Statistics matters in interpretations of non-traditional stable isotopic data

Increasing volumes of of non-traditional stable isotope data have brought new opportunities to gain important insights into geochemical and planetary processes. However, there is a worrysome trend that the isotopic data are interpreted in a fashion that its statistical approaches are chosen subjectively. This communication summarizes the rules regarding calculating the mean, standard deviation and relative standard deviation of a population, as well as error propagation and significant digits. These rules should be used when reporting geochemical data, especially for isotope ratios. Using two examples, I show that statistics matters in isotopic data interpretation.