Every company or institute that has to handle materials also has to deal with solving practical sampling problems. Those sampling problems include: establishing the number of samples to take, the size of the samples, and, at least equally important, the method by which the uncertainty caused by the sampling is estimated. In addition, there are various types of materials ranging from solids, liquids to gaseous materials. Also the objectives of sampling vary: sampling may be performed for quality control of raw materials, for environmental monitoring, for resource estimation in mining, or for many other possible purposes. No single approach can be expected to provide an answer in all scenarios. This book brings the different fundamental approaches to the problem of material sampling together. Five experts in the field of sampling have contributed chapters explaining each approach and its recent developments. These provide the underlying data as much as possible. In addition, tools are provided on the accompanying cd to allow the reader to verify a large number of data analyses presented in this publication. The book is intended for scientists working in the research area of material sampling and companies or institutions that have to solve practical sampling problems.