This is an experimental and theoretical program on the statistical mechanics and kinetics of microstructure evolution. The experimental approach developed for creating and analyzing well-characterized microstructures from partially solidified unary melts is extended to binary metallic alloys and organic systems. A new statistical theory of phase coarsening based solely on self similarity and global microstructure constraints is pursued. Thermal decay measurements and quantitative stereology is employed to provide a definitive link between the meanfield and lengthscale descriptions of evolving microstructures.