An emerging theme in computational materials science is that of multiscale modelling. While the definition of 'multiscale modelling' is still developing as new applications appear, a broad interpretation includes efforts to exploit insights arising either from distinct methodologies or from the attempt to incorporate multiple mechanisms into the same modelling paradigm. Though multiple scale models are not new, the topic has recently taken on a new sense of urgency, due to the recognition that brute force computational approaches often fall short of allowing for direct simulation of both the characteristic structures and temporal processes found in real materials. As a result, a number of approaches are now finding favor in which ideas borrowed from modelling paradigms are unified to produce more powerful techniques. This book, first published in 1999, brings together experts to both exchange ideas on how to link methodologies at different length scales, and to outline the most promising future approaches. Topics include: modelling dislocation properties and behavior; defect dynamics and microstructural evolution; crystal defects and interfaces and noncrystalline and nanocrystalline materials.