Book excerpt: The developments of new algorithms in applied mathematics, of new concepts in computer sciences, and of new hardware in computer technology have led to an immense output of data streams describing the solutions of important physical or technological problems. In order to understand and to explore the results of calculations, new visualization methods have been developed. These novel methods are indispensable for mathematicians and engineers working with problems such as flow theory or elasticity. These proceedings contain selected contributions from the DFG-workshop on visualization, held at the University of Paderborn, January 18--20, 1994, and will be of interest to researchers in the above mentioned fields.