Specificity and practice of validation of forensic methods

The metrological validation of forensic methods is an effective precedure for confirming the reliability of the results obtained for researching forensic objects. The lack of a regulatory framework requires a study of the validation methodology and the specifics of forensic methods. In connection with two types of controlled indicators (quantitative and qualitative), the methods are divided into two types: forensic measurement methods (FMM) and testing methods (FTM). It was shown that the validation of FMM coincides with the corresponding procedure for quantitative chemical analysis methods. The specifics of validation of forensic testing methods related to parameters (requirements for targeted use) and the organization of the experiment were considered. Specific examples of the use of blind tests in the validation procedure are given. Statistical evaluation of the reliability parameter of the test method is based on the calculation of the number of false/true results. A terminology and formulas for calculating different indicators of false/true positive/negative results of qualitative testing are presented. The possibilities of assessing the reliability limits of validation results of the FMM and FTM methods, as well as the results of measurements in comparative studies of the objects of expertise for solving identification problems are shown. The specifics of validation of forensic methods used in threshold tests have been studied in detail and shown.

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