4. Assessing the uncertainty of analytical results

4.1 Concept of uncertainty

The purpose of a measurement is to assign a value to the measurand, the measurand in the vocabulary of metrology being the quantity we seek to measure.

The hazards of any measurement process lead us to "estimate" the measurands and assign them the value in which we are most confident. Our "measurement result" variable can therefore be likened to a random variable whose distribution can be summarized by two parameters: a central tendency parameter, which is estimated by the mathematical expectation of the distribution, i.e. the value we announce, and a dispersion parameter, the standard deviation of the distribution, also known as the standard uncertainty.

If we accept this, then the definition of uncertainty...