This book provides a forum for researchers who have been using a variety of electrical measurements as a means to obtain microstructural information about their materials. Microstructure in this context includes features at all length scales - atomic to macroscopic. Even though numerous examples of microstructure/electrical property correlations exist, this book focuses on the myriad of applications that have already been successful. In addition, advances in techniques for the interpretation of data and modelling of materials-related phenomena are emphasized. The effects of percolation and connectivity of electrical paths are of particular interest as they determine the resultant electrical response. These in turn are intimately linked to how a material is processed, what phases it contains, and how the phases are distributed in real space. All classes of materials are covered including semiconductors, electroceramics, biological materials, polymers, metals, geomaterials and a variety of composites. Topics include: advances in localized electrical testing; semiconductor and microelectronic applications; magnetic and polymeric materials; dielectrics and ferroelectrics; varistors; ionic and mixed conductors and composites and percolation systems.