Evaluation of evidence in the form of physicochemical data
The application of numerous analytical methods to the analysis of evidence samples returns various kinds of data (Chapter 1), which should be reliable. Confirmation that the data are reliable can be obtained when the particular analytical method is validated, that is, it is confirmed by the examination and provisions of objective evidence that the particular requirements for a specific intended use are fulfilled. Parameters such as repeatability, intermediate precision, reproducibility, and accuracy should be determined during the validation process for a particular quantitative technique. Therefore, statistical quantities such as standard deviations and relative standard deviations are usually calculated, and a regression/correlation analysis as well as an analysis of variance are usually carried out during the determination of the above-mentioned parameters (Chapter 3). This means that the use of statistical tools in the physicochemical analysis of evidence should not be viewed as a passing fad, but as a contemporary necessity for the validation process of analytical methods as well as for measuring the value of evidence in the form of physicochemical data.
It should also be pointed out that in general, representatives of the administration of justice, who are not specialists in chemistry, are not interested in details such as the composition of the analysed objects, except in a situation such as the ...