Book excerpt: This book introduces and details the key facets of Combined Analysis—an x-ray and/or neutron scattering methodology which combines structural, textural, stress, microstructural, phase, layer, or other relevant variable or property analyses in a single approach. The author starts with basic theories related to diffraction by polycrystals and some of the most common combined analysis instrumental set-ups are detailed. Powder diffraction data treatment is introduced and in particular, the Rietveld analysis is discussed. The book also addresses automatic phase indexing—a necessary step to solve a structure ab initio. Since its effect prevails on real samples where textures are often stabilized, quantitative texture analysis is also detailed. Also discussed are microstructures of powder diffraction profiles; quantitative phase analysis from the Rietveld analysis; residual stress analysis for isotropic and anisotropic materials; specular x-ray reflectivity, and the various associated models. Finally, the book introduces the combined analysis concept, showing how it is superior to the view presented when we look at only one part of the analyses. This book shows that the existence of texture in a specimen can be envisaged as a way to decouple ordinarily strongly correlated parameters, as measured for instance in powder diagrams, and to examine and detail deeper material characterizations in a single methodology.