The materials dealt with in this volume include wood, concrete, various metals, composites, ceramics, and porous geological media. Obviously, the properties and serviceability of such materials vary widely, and an almost universal theme in their testing is that the properties depend on the scale at which the analysis or observation is made. At each scale, probability plays an important role, where the word probability is used in a wider sense than the classical one. The book begins with a review of progress over recent years, identifying key questions that remain open. One point is how to...