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By measurements of NORM (residues,contaminated areas,etc.),usually gamma spectrometry,a collective of measurement results (Bq/g; Bq/cm2) is generated.A test statistic (e.g.median,mean,95th percentile,95 %-upper confidence limit of mean) is determined from the collective of measured values by means of a statistical evaluation algorithm.There are following possibilities to apply this test statistic: It can be compared with the current control limits of NORM regulations or it is used as a basis for dose assessments.First,we investigate the relationship between dose limit (e.g.1 mSv/a) and derived control limits (e.g.1 Bq/g).Using examples from practice,ultimately we show the influence of radionuclide ratios of different types of NORM on the results of evaluation of NORM measurements.Secondly,different statistical methods for the calculation of the test statistic will be presented.The classical statistical methods are compared with the modern numerical methods.We found a robust,efficient and nonparametric numerical procedure: the bootstrap-method1 with two modifications: (1) implementation of the measurement uncertainty; (2) application of the BCa2 method.The various methods (classical and numerical) are applied to measured results from the practice of radiation protection.We take practice-examples with less than 30,more than 30 and even more than 100 individual measurement results.The results of application of classical and numerical statistical methods on the practice-examples are compared and discussed in detail.