Testing methods experimental design requirements

It is clear that a method that is only to be used 5 or 10 times requires much less vigorous testing than a method that is to be used as a quality assurance method over several years. The considerations for designing protocols for a ruggedness test are described for selecting both factors for testing and experimental designs in the relevant sections of this chapter. 

This efficient statistical test requires the minimum data collection and analysis for the comparison of two methods. The experimental design for data collection has been shown graphically in Chapter 35 (Figure 35-2), with the numerical data for this test given in Table 38-1. Two methods are used to analyze two different samples, with approximately five replicate measurements per sample as shown graphically in the previously mentioned figure. 

In most cases, data that are obtained through theoretical approaches (literature, data bases, software programs) may not be sufficient for final plant design. Experimental work is usually required on various scales depending on the extent of reactivity. Therefore, the application of well designed experimental test methods is of prime importance to define hazardous conditions. Numerous test methods are available using a variety of sample sizes and conditions. 

The text reviews the methodology of kinetic analysis for simple as well as complex reactions. Attention is focused on the differential and integral methods of kinetic modelling. The statistical testing of the model and the parameter estimates required by the stochastic character of experimental data is described in detail and illustrated by several practical examples. Sequential experimental design procedures for discrimination between rival models and for obtaining parameter estimates with the greatest attainable precision are developed and applied to real cases. 

Recordkeeping is essential and it begins with a protocol that delineates the objectives of the study and outlines the experimental design and methods. To comply with the GLP requirements, the final test report on the toxicological effects of the test chemical substance includes specific descriptions. These may be listed as ... 

To evaluate the predictive properties, which is rarely done in method optimization, an external validation can be made (1,7). This requires an external test set, which consists of experiments at other conditions than those of the experimental design. Again the experimental and the predicted responses are compared and the residuals evaluated. 

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