The 1995-1996 program at the Institute for Mathematics and its Applications was devoted to mathematical methods in material science, and was attended by materials scientists, physicists, geologists, chemists engineers, and mathematicians. This volume contains chapters which emerged from four of the workshops, focusing on disordered materials; interfaces and thin films; mechanical response of materials from angstroms to meters; and phase transformation, composite materials and microstructure. The scales treated in these workshops ranged from the atomic to the macroscopic, the microstructures from ordered to random, and the treatments from purely theoretical to highly applied. Taken together, these results form a compelling and broad account of many aspects of the science of multi-scale materials, and will hopefully inspire research across the self-imposed barriers of twentieth century science.