The papers collected in this volume were originally presented at the conference on Design and Decision Support Systems in Architecture and Urban Planning that was held in Mierlo, the Netherlands in July 1992. This conference was organized as one of the events celebrating the 25th anniversary of the founding of the Faculty of Architecture, Building and Planning at Eindhoven University of Technology. The organizing committee had a strong feeling that many interesting developments in this area were emerging within different institutional frameworks and informal networks that do not interact frequently. For example, scholars working on architectural problems are not particularly familiar with computer applications in urban planning. Likewise, although many computer-aided design systems claim to be based on principles of design methodology, serious discussions on the methodological underpinnings of such systems are relatively scarce. Consequently, we may have little opportunity to learn how scholars in closely related disciplines approach specific design or planning problems.