The role of conceptual diagrams in the architectural design process: Case studies of the First Unitarian Church by Louis Kahn, the Staatsgalerie by Stirling and Wilford Associates, and the Jewish Museum by Daniel Libeskind (New York, Germany)

This thesis investigates the conceptual phases of design during when designers formulate new ideas, develop them, and often change them, and the role of conceptual diagrams in the evolution of these ideas. The thesis poses three questions. First, what is the nature of the initial phases of design? Second, what are the roles of conceptual diagrams in the initial phases? Third, how to study the initial phases of design?; Expert architects' accounts of their design process often describes the initial phases of design as a period of incubation at the end of which they achieve a complete understanding of their design situation and a full-fledge design. In contrast to these accounts, historical materials from architectural archives portray rather a more complex process during which design proceeds through several iterations and changes. Research in the area of design studies has also corroborated to refute expert designers' accounts by investigating the design process. Research in this area, however, has been inconclusive in providing a rich understanding of the initial phases of design. First, researchers in design have described the initial phases of design differently. Goel and Pirolli (1992) claim that design evolve in two distinct and sequential phases, i.e., problem structuring and problem solving. Schön (1988) characterizes design as construction of a framework rather than a sequential process from problem structuring to problem solving. Maher et al. (2003) describe design as a co-evolutionary process during which problem structuring and problem solving evolve interactively. Second, researchers in the area of design studies have often investigated design processes through simplified design tasks by using the protocol analysis method.; This thesis addresses some of the discrepancies between expert architects' accounts and historical documents and among researchers in design studies about the nature of initial phases of design. It does this through offering a methodology thus far not used in design studies: the cognitive-historical analysis method. The method has been proven to be effective in describing cognitive processes in scientific discovery and has potential to provide a richer and contextually embedded understanding of the design process also. In this thesis, the method is applied to three cases from architectural design: the First Unitarian Church by Louis Kahn, the Staatsgalerie by Stirling and Wilford Associates, and the Jewish Museum by Daniel Libeskind. The archival research for these case studies, indeed, uncovered one particular kind of representation, conceptual diagrams, that designers use in the initial phases of design to explore design ideas and design schemes. The results from the case studies indicate that conceptual diagrams mediate the exploration in two spaces in design: the problem structuring space and the solution space. The former is characterized by conceptualization of design situations, whereas the latter is characterized by a search for a meaningful spatial configuration corresponding to the conceptualization. In the three design processes that were studied, the two phases of design are coalesced through conceptual diagrams which mediate the dual exploration in the problem space and the solution space. The proposal of this thesis is that conceptual diagrams are double-referential, thus through their structural correspondence to their target domains, they align the structures of their respective target domains.