This volume, presenting four theses completed under the editor's direction at the institute for the Learning Sciences at Northwestern University, elaborates Case-Based Teaching Architecture. A central tenet of this architecture is the importance of acquiring cases, and being able to retrieve and use those cases to solve new problems. The theses presented address the problems of building case bases, indexing large amounts of data contained within those case bases, and retrieving information on a need-to-know basis. They also reflect the work of researchers at the Institute for the Learning Sciences to design tools that enable software programs to be built more effectively and efficiently.