ABSTRACT
The chapter begins with a brief description of the essential components of a technical project. Next is a short section on elementary statistical principles that reviews some of the necessary concepts used in the immediate sections that follow. This is succeeded by sections on the principles of measurement and calibration and then some basic sampling theory. A more extensive section on statistical analysis is next, which then leads to the principles of quality assessment and control . The chapter concludes with a discussion of the topics of precision, bias, and uncertainty in laboratory testing. The word uncertainty is used in two different senses in the chapter, first as a generic term as defined above and second as a particular or specific term that defines a range or interval for any point estimate of a measured value. This distinction is readily apparent in the sense of its use, and this topic is fully discussed in the last section and in some of the annexes. Annex A gives some general statistical tables useful for the various statistical analysis algorithms. Annex B describes a statistical model for the testing process, which is also discussed in the last section of the chapter. Annex C gives a procedure for evaluating accuracy and bias. Precision is expressed in terms of within-laboratory variation, called repeatability, and between-laboratory variation, called reproducibility, and since these are important concepts, the calculation procedure for these two precision parameters is given in Annex D. These annexes should be consulted as indicated and as needed in the various sections of the chapter.
