Effect of experience and sketching on design productivity in the early phases of architectural design

Because of their ill-defined nature, design problems cause complex and difficult-to-analyze design processes where outcomes are differentiated and the ways followed to reach outcomes are personal. In the early design phases where important decisions are taken in architectural design, the way how designer address the problem plays a decisive role for design process and outcomes. At this point, it is seen that the expertise in architectural design becomes important because expert and novice architects address the design problems in different ways. This leads to significant changes in the structure of design process, and thus the end product is also affected. Besides the way of addressing problems according to design expertise, another important factor that affects -and more importantly- forms the decisions taken in the early phases of architectural design is the medium/tool that is used for designing. Sketch medium as a "thinking tool" in the early phases of architectural design, which prepares the ground for creativity and productivity by supporting visual reasoning of the designer, enables the designer to relate between the imaginations in mind (internal representations) and the physical images created on paper (external representations). The designer creates new images and design ideas by questioning and transforming these relationships during the design process. In this context, the purpose of the thesis is determined as to research the effect of experience and sketching on design productivity in the early phases of architectural design. Within the scope of the thesis, in order to observe the effect of experience and sketching on design productivity in architectural design, the early design phase is examined where architects generate ideas with creative visual thinking by sketching to make the main design decisions. In this context, two different experience groups were identified to observe the effect of experience in the early phases of architectural design, and design studies were carried out with two participants from each of these experience groups. The first group consists of senior architecture students who are considered as novice, while the second group consists of people with 8-10 years of professional architectural experience who are considered as experienced. Participants were asked to generate a design proposal to the same architectural design problem through sketching. The subject of the architectural design problem to be used in design experiments were determined as housing design, and the necessary documents and architectural program were given to the participants. The housing function was chosen by considering that all participants with different experiences, even those who didn't have any architectural experience, had somewhat experience. After design problem and participants were determined, protocol studies were carried out with participants who are using think-aloud method while sketching to produce a design proposal to the given problem, and their design processes were recorded with the camera. Firstly, the verbal expressions obtained from video recordings of each participant's design process were transcribed and segmented as design moves, then coded according to sketching action. While parsing design moves, the designer's verbal expressions and sketches are evaluated together and focused on design decisions that change the course of the design process by little thought changes. In this way, micro-level design decisions that lead to spatial, functional, and formal changes in the design process have been identified as design moves. Linkographs were constructed by detemining the links between design moves. The link between two design moves is determined by the content of the moves. All design moves are examined one by one by querying whether each design move is contextually linked to previous moves. Design productivity of each participant were determined through individual design process analysis by using linkographs. Finally, comparative analyses of design productivity, within each experience group and between groups, was included. As a result of protocol studies and linkograph analyses, important findings have been reached revealing the effect of experience and sketching on design productivity in the early design phase. Accordingly, it has been seen that besides the general architectural experience that participants have, the experience on the specific problem area (housing design) is significant for the emergence of design productivity. Having the problem-specific experience affects design productivity positively in both senior architecture students' group and experienced architects' group. Another important result is that the experience of the participants and their rate of sketching in the design processes are parallel. In this context, it has been observed that the participants having more experience have a higher rate of sketching by using sketch medium more efficiently, and they generate a great majority of their design ideas through sketching. It has been observed that the high rate of sketching associated with experience affects positively to link index, critical move rate and linking pattern rates which are used to determine design productivity in linkograph analyses, and consequently contributes to occur a productive design process.