Methods of soil analysis. Part 1. Physical and mineralogical methods / Методы анализа почв. Часть 1. Физические и минералогичекие методы

The experimenter is confronted nearly every day with the examination of results from his or her own experiments as well as those of others. There is a need to know the methods by which the data were obtained and what confidence can be placed in the numerical results. Significant aspects of these matters involve the principles and methods of statistics, and the jective of this chapter is to describe the basic ideas of statistics that are relevant to errors of observations and numbers derived from these observations. 
A measurement is a quantification of an attribute of the material under investigation, directed to the answering of a specific question in an experiment. The quantification implies a sequence of operations or steps that yields the resultant measurement. Thus, the concept of measurement may be said to include not only the steps used to obtain the measurement but also use of the measurement by the experimenter to draw conclusions. 
The measurement process provides a result which serves as part of the basis upon which an experimenter makes a judgment about the attribute under investigation. Some judgments may require a more reliable basis than others. Desired reliability in the measurements will depend on the purpose for which the measurements are to be used, but the degree of reliability may be limited by resources available to the experimenter <...>