Book excerpt: This book demonstrates the potential of novel in-situ experiments, performed on microscopic and macroscopic length scales, for investigating localized deformation processes in metallic materials, particularly their kinetics and the associated evolution of local strain fields. It features a broad methodological portfolio, spanning optical and electron microscopy, digital image correlation, infrared theromgraphy and acoustic emission testing, and particularly focuses on identifying the localized microscopic deformation processes in high-strength/high-ductility CrMnNi TRIP/TWIP (TRansformation Induced Plasticity/TWinning Induced Plasticity) steels. Presenting state-of-the art methodology applied to topical and pertinent problems in materials engineering, this book is a valuable resource for researchers and graduate students working in the field of plasticity and deformation of structural materials.