These symposium proceedings from the 1998 TMS Fall Meeting examine the relationships between mechanical behavior and microstructural evolution that must be quantified to develop predictive models for hot deformation. Issues addressed include constitutive modeling; process design and modeling; laboratory simulation of large scale hot working processes; the evolution of microstructure; texture, damage, dynamic precipitation, recovery, and recrystallization processes; creep and superplastic deformation; and the ability to predict phenomena such as corrosion and formability after hot deformation.