This part of ISO 11648 establishes the general principles for the application and statistical treatment of the sampling of bulk materials. It also provides general guidance and examples for estimating necessary variances and checking precision and bias when the avarage value of a quality characteristic is investigated. Furthermore, this part of ISO 11648 gives information relating to the statistical analyses af serial data, by the use of variograms and correlograms. This part of ISO 11648 also defines the basic terms with definitions for the sampling of bulk materials. These terms are necessary for providing a better understanding of sampling techniques as