KATHOLIEKE UNIVERSITEIT LEUVEN FACULTEIT TOEGEPASTE WETENSCHAPPEN DEPARTEMENT ARCHITECTUUR, STEDENBOUW EN RUIMTELIJKE ORDENING Kasteel van Arenberg, B-3001 Leuven In case of architectural design Critique and praise of Case-Based Design in architecture Jury: Proefschrift voorgedragen tot Voorzitter Prof. Joos Vandewalle, vice-decaan het behalen van het doctoraat Prof. Herman Neuckermans, promotor in de toegepaste wetenschappen Prof. André Loeckx Prof. Jan Schreurs door Prof. Johan Wagemans Prof. Albert Dupagne (Université de Liège) Ann Heylighen Prof. Rivka Oxman (Technion Haifa) UDC 72.011 Mei 2000 Katholieke Universiteit Leuven – Faculteit Toegepaste Wetenschappen Kasteel van Arenberg, B-3001 Leuven (Belgium) Alle rechten voorbehouden. Niets uit deze uitgave mag worden vermenigvuldigd en/of openbaar gemaakt door middel van druk, fotokopie, microfilm, elektronisch of op welke andere wijze ook zonder voorafgaande toestemming van de uitgever. All rights reserved. No part of this publication may be reproduced in any form by print, photoprint, microfilm or any other means without written permission from the publisher. D/2000/7515/17 ISBN 90-5682-248-9 For my grandmother Acknowledgements Five years ago, I had to decide on a subject for my graduate’s thesis. Professor Herman Neuckermans made the suggestion to have a look at Case-Based Design, at that time a ‘hot topic’ in the field of CAAD. Computers were not exactly what I would call my cup of tea, but I nevertheless accepted his suggestion – not in the last place because it would enable me to spend one semester at the ETH in Zürich. Although the thesis became an unqualified success in terms of scores, it left me with an uneasy feeling. Judging from the literature, the applications of Case-Based Design in architecture were not (yet) convincing. Yet, the underlying ideas seemed so plausible, that I could not dismiss it as the umpteenth flash in the CAAD pan. Immediately after my graduation, I received a grant from the Fund for Scientific Research (FWO) Flanders, which enabled me to pursue the matter with a doctoral research. During the course of this research, I’ve had a lot of help and support. It would be impossible to mention everyone I met and exchanged opinions with, who gave me suggestions and encouragement. But among them, I feel a special obligation to thank, above all, Professor Neuckermans, who generously invited me into his CAAD-lab, thus giving me access to his personal expertise, his research budget (especially the part meant for travelling), his library and – last but not least – the daily help and friendship of his other CAAD-assistants. Among them, a very special thanks goes to Benjamin Geebelen, Bart Geeraerts and Kris Nuyts for the 1013 ways in which they have contributed to – and once in a while kept me from – my work. In 1997/1998, the CAAD-lab was temporarily reinforced by Raf Segers, the first thesis student I’ve supervised and, more importantly, the living dynamo behind DYNAMO. The data analysis for the evaluation of DYNAMO and the experimental study on the effects of examples was performed in close collaboration with Dr. Ilse Verstijnen from the department of Psychology. Collaborating with the “dépendance in de Tiensestraat” – Professor Johan Wagemans, Ilse and Pim – was not just instructive, I really enjoyed it. The collaboration with Jan Bouwen from the department of Applied Economics was less structural, and above all less self-evident, but therefore not less fruitful. I am indebted to him for his exchanged opinions, suggestions and encouragement in the course of my research, and for his detailed constructive comments on earlier drafts of this text. In addition to Professor Wagemans, I would like to thank Professor André Loeckx and Professor Jan Schreurs for the stern and critical, but productive way in which they accomplished their task as members of the supervising committee. Thanks also to Professor Albert Dupagne (Université de Liège) and Professor Rivka Oxman (Technion, Haifa), who have accepted to be on the jury. I am, of course, extremely grateful to the architects I’ve interviewed – Jan Delrue, Mauro Poponcini, Paul Van Aerschot, Werner Van dermeersch, Paul Vermeulen and Peggy Winkels. They have given their precious time very generously and have made the writing of chapter 4 a fascinating and thoroughly rewarding experience. In addition to the CAAD-colleagues, I was given considerable help (and support) by many other staff members and students of our department. In particular, I would like to thank all those who have contributed to the experiments. They are (amongst others): the students and the titular of the 2nd year Basic Design course; the studio teachers Evi Corne, (once again) Mauro Poponcini, Ann Verdonck and Hans Verplancke; the external judges Guido Geenen and Ivo Vanhamme; the students and the titular of the 4th year design studio; the studio teachers Hans De Petter, Leo Van Broeck and (once again) Ivo Vanhamme; and the external judges Heike Löhmann and Piet Stevens. Karen Depoortere and Paul McHale were continuously helpful during my work by keeping an eye on the grammar and spelling of the text. For encouraging me all the while, not only as I worked on this thesis, but also during my study, I am very grateful to my parents and my sister and, for his daily on- line support, to Toon. They saw me through the good times and the bad, and were always convinced that I would succeed, especially when I was not. Thanks are due to many friends who have supported me in multiple ways. However, particular thanks go to Liesbet, Veerle and Gunther for their extra encouragement during the last months, and to the members of the working group ‘Woman and University’, for holding up themselves as stimulating example. I dedicate this work to my grandmother, who had to miss me on many Sunday afternoons. My talents are hers, the opportunities I was given are the ones she should have got. In case of architectural design Critique and praise of Case-Based Design in architecture Architects are said to learn design by experience. Learning design by experience is the essence of Case-Based Design (CBD), a sub-domain of Artificial Intelligence. Part I critically explores the CBD approach from an architectural point of view, tracing its origins in the Theory of Dynamic Memory and highlighting its potential for architectural design. Seven CBD systems are analysed, experienced architects and design teachers are interviewed, and an experiment is carried out to examine how cases affect the design performance of architecture students. The results of this exploration show that despite its sound view on how architects acquire (design) knowledge, CBD is limited in important respects: it reduces architectural design to problem solving, is difficult to implement and has to contend with prejudices among the target group. With a view to stretching these limits, part II covers the design, implementation and evaluation of DYNAMO (Dynamic Architectural Memory On- line). This Web-based design tool tailors the CBD approach to the complexity of architectural design by effecting three transformations: extending the concern with design products towards design processes, turning static case bases into dynamic memories and upgrading users from passive case consumers to active case-based designers. Case-Based Design in architectuur Een kritische studie Architecten, zo beweert men, leren ontwerpen uit ervaring. Leren ontwerpen uit ervaring is de essentie van Case-Based Design (CBD), een sub-domein van de Artificiële Intelligentie. In deel I wordt de CBD-benadering onderworpen aan een architectuurkritische studie. CBD is gebaseerd op de Theorie van het Dynamische Geheugen, en biedt het architectuurontwerpen heel wat voordelen. Zeven CBD systemen worden doorgelicht, ervaren architecten en ontwerpbegeleiders worden geïnterviewd, en de impact van concrete ontwerpervaring (cases) op de ontwerpprestatie van architectuurstudenten wordt experimenteel onderzocht. Hieruit blijkt dat CBD bijdraagt tot een beter inzicht in hoe architecten leren ontwerpen, maar beperkt is qua visie op het architectuurontwerpen, implementatie en gebruikerscontext. Deel II beschrijft het ontwerp, de implementatie en de evaluatie van een Dynamisch Architectuur-Geheugen On-line (DYNAMO), een ontwerpinstrument dat de CBD-aanpak poogt af te stemmen op de complexiteit van het architectuurontwerpen. Het verschuift de aandacht van ontwerpproducten naar ontwerpprocessen, vervangt statische case bases door een dynamisch geheugen, en maakt van de gebruikers actieve case-producenten in plaats van passieve case- consumenten. CONTENTS Introduction 1 Chapter 1: Conceiving architecture 1.1 The complexity of architectural design 9 1.2 Knowledge engineering in architectural design 11 1.2.1 Things to know 11 1.2.2 Ways of knowing 12 1.3 Knowledge channels for conceiving architecture 14 1.3.1 Heuristics 16 1.3.2 Analogy 17 1.3.2.1 Iconic analogy 19 1.3.2.2 Canonic analogy 21 1.3.3 From analogy to metaphor (and back to analogy) 22 1.3.4 Type in a nutshell 25 1.3.5 Types and instances 30 1.3.6 A grid across a complex field 34 1.4 Prior notices 36 Part I. A critical exploration of Case-Based Design in architecture Chapter 2: What is Case-Based Design based on? From Artificial Intelligence over Dynamic Memory to Case-Based Design 2.1 Artificial Intelligence 42 2.1.1 What? 42 2.1.2 Why? 43 2.1.3 How? 43 2.2 Case-Based Reasoning: theory, model and application 44 2.2.1 The Theory of Dynamic Memory 45 2.2.1.1 Scripts 45 2.2.1.2 Reminding 46 2.2.1.3 Reminding and problem solving 46 2.2.2 The cognitive model behind CBR 47 2.2.2.1 Structure and organisation of knowledge 47 2.2.2.2 Reasoning processes 48 2.2.2.3 Learning 50 2.2.2.4 Generalised knowledge 50 2.2.3 Applications 51 2.2.3.1 Constructing Case-Based Reasoners 51 2.2.3.2 Investigating human intelligence 52 2.3.