Abstract
For evaluating the analytical data on reference samples, the following approach is proposed: 1. Analytical methods used are critically reviewed. 2. Outliers are eliminated. 3. Normality of the results is tested. 4. If normality of the results can be accepted, arithmetic mean, its confidence interval and coefficient of the precision are computed. 5. If the results are not normally distributed, median and its statistical characteristics are given. 6. For sets of data with anomalous skewness, logarithmic and lambda transformations are useful approaches.