ArchieTutor is an experiment ill combining case-based and multimedia technologies to support tile teaching of architectural design. It provides all architectural student with access to a library of past design cases, and enables the student to retrieve and browse through cases that are similar to a given design problem. Tile cases are annotated with design lessons learned from thenl. In addition, the cases are explicitly related to relevant domain models, and design principles and guidelines. The system uses these principles, guidelines and models to explain, justify or critique a design choice, and to elaborate on a design lesson. In addition, it uses cases to illustrate a given principle, guideline or model.