The topic of this conference is various aspects of similarity solutions of differential equations (solutions obtained by the classical Lie group method or generalizations), the occurrence of similarity solutions in applicable situations, the study of similarity solutions of particular equations, and the relation of similarity solutions to more general solutions of the relevant equations. Subjects to be discussed include travelling waves for reaction-diffusion equations, blow-up and quenching problems, equations soluble by inverse scattering and the Painleve transcendent equations, and boundary layer problems. This grant will help support a conference to be held at the University of Pittsburgh on April 26-28, 1991, whose goals are to provide a forum for the exchange of ideas and results on the leading edge of research in this topic.