Pirita Seitamaa-Hakkarainen
The visual representation of a product and the role of visualization
have recently become a central issue in design research because much of
design is concerned with concrete qualities of the design elements to be
designed, and effective ways to achieve plausible solutions (Goel,
1995; Oxman 1997). Lawson (1990) argued, that in craft process visual
representations are not so commonly used; indeed, crafts person
traditionally designed objects as they made them. However, sketching is
an integral part of art, craft and design activities, and drawing is
generally the most important thinking tool for the designer (Eisentraunt
& Günther, 1997; Ferguson, 1992; Goel & Pirolli, 1992; Goel,
1995; Oxman, 1997; Purcell & Gero, 1998; Suwa & Tversky, 1997).
During their education, designers are required to become skillful at
freehand drawing, including sketching rapidly and accurately.
Eisentraunt and Günther (1997), further have claimed that these
drawings, cannot be created or supported easily with CAD-systems (see
also Suwa & Tversky, 1997).
Nonetheless, drawing is most importantly to seen to represent mental activity, and the main issue is the complementary relationship between two forms of representation, i.e., verbal-conceptual and visual-graphic (Akin & Lin, 1995; Goel, 1995; Lawson & Loke, 1997; Oxman, 1997). In other words, the activity of designing includes the formulation of mental representations of a design product, crystallizing design ideas in early design processes. According to Goel (1995), designers use many symbol systems and these varied symbol systems are correlated with different problem-solving phases. Designers examine their designs in several overlapping ways, i.e., through differing types of the sketches, notes and models. Goldschmidt (1997) divides representations into internal (e.g., imagination, silent thinking) and external (e.g., expressed in words, drawings, written). According to her, in design, visual representations are most commonly used to express ideas. Yet, the way a designer modifies and adapts visual representation through sketching and re-sketching is still one of the least understood phenomena in design research (Oxman, 1997; see also Goel, 1995).
Schön (1983) described design activity as a reflection-in-action, where the designer is engaged in a visual conversation with the design by sketching, inspecting and revising. Accoringly, Lawson (1990), emphasized that the designer has a conversation with the drawing (see also Ferguson, 1992; Goel, 1995). “Conversation” with drawings means that the designers’ internal processing allows reflective evaluation and exploration of new ideas, as well as their easy and rapid modification (Goel, 1995; Schön, 1983). However, the meaning of sketches, patterns and notebooks is also traditionally seen as facilitating communication of the design ideas with clients. These sketches also serve as a documentation tool for the design project (i.e., portfolio). A successful representation requires good externalization of ideas, enabling the client to accept the idea, as well as adequate communication to convey complete information to him or her. Sketches are usually supplemented with concepts of design ideas, visualization of the design and its details, and written specifications, material maps or even small-scale models (Anttila, 1993; Ferguson, 1992; Goel, 1995; Lawrence, 1993). This communicative role, however, which may figure in the actual professional design process, is excluded from the scope of present study. Instead, the main emphasis will be on the internal design process in which ideas are sequentially transformed in the form of external representations (i.e., sketches); this is a medium through which design processes are made manifest.
Visual representation in design is viewed here as a transaction between conceptual and visual knowledge, which enables the designer to immediately control, promote or evaluate specific characteristics of the design in progress. Visual aspects of the design are explored and reflected in the produced drawings and sketches (Anttila, 1993; Ferguson, 1992; Goel, 1995). Accordingly, drawings not only record human thought, but can also simulate it (Akin & Lin, 1995; Goel, 1995; Oxman, 1997). Moreover, visual representations, such as sketches, are seen as a graphical problem solving method, in which conceptual ideas of the design are concretized in visual form. Sketching ideas in external form makes it possible to evaluate and compare those representations (Goel, 1995; see also Eisentraunt & Günther, 1997; Suwa & Tversky, 1997). Goel (1995) analyzed the role of sketching and the development of sketches by distinguishing syntactic and semantic levels of the drawings and identifying transformations of those levels in the process of sketching. According to him, the sketches can be identical to or variations of previous drawings, but a drawing is never exactly as an old one. Moreover, drawing transformations can happen in a lateral or a vertical manner. Lateral transformation indicates the exploration of the slightly different design idea and widening the possibilities; vertical transformation entails producing sketches in deepening and more detailed versions of the same idea (Goel, 1995; see also McGowan, Green & Rodgers, 1998).
Cognitive research on expertise has revealed that human beings have only limited cognitive resources; such as time, memory, or computational power. For example, Norman (1993) argued that human cognitive resources are highly overestimated; without external aids humans have only a limited memory and reasoning capacity. Higher cognitive accomplishments require that an individual use many kinds of external representations as sources of knowledge, organizers of activity, and in general extensions of his or her cognition. By using tools of visualization and writing, humans are able to reduce the cognitive processing load and take on more complicated problems than would otherwise be possible. Through externalization of one’s thought, otherwise implicit meanings can be explicated and information represented in a more abstract form (Olson, 1994). Through visualization, advantages of the powerful human visual system can be used to facilitate problem solving. In sketches the designer has the potential to handle simultaneously huge amounts of information. Drawing and written notes also serve as memory aids for the designer. In this sense, sketches and notes can be seen as physically distributed cognition (Norman, 1993; see also Perkins, 1993), since they facilitate limited cognitive capacity of the human designer.
According to Akin (1986), visual representation is connected with specification of design issues, and design sketches are abstract models of real objects (see also Ferguson, 1992; Goel, 1995). Further, visualization of ideas is a most dynamic process; sketches can be rapidly transcribed and modified, enabling easy exploration and evaluation of various possibilities for design problems. Rough sketches indicate visually how the work will look and how the product will function (Ferguson, 1992). Using several visual representations (idea sketches or thinking sketches, prescriptive and final sketches and study models), a designer generates alternative solutions and tests them before bringing the designed product to production (Akin 1986; Ferguson 1992; Goel, 1995).
Visual representations play varied roles in the design process (Fergusson, 1992; Goel, 1995). Fergusson (1992) has distinguished three different types of drawings; thinking sketch, prescriptive sketch and talking sketch. Thinking sketches are the first step to presenting a conceptual or visual idea; they are usually done very quickly, are roughly sketched and do not include details. They are usually large-scale drawings, showing the whole product in an abstract way (see also Eisentraunt & Günther, 1997). Later, one of the sketches may form the basis for the redrawing and more detailed experimentation. Prescriptive sketches are modifications of the basic ideas, but with greater detail, and they are usually scaled. In talking sketches, the ideas are constantly drawn in discussion with others, and such sketches are used to facilitate explanation of technical points or simply to point out features that are not yet worked out (Fergusson, 1992). According to Fergusson (1992), only when the sketch has been made into a scaled drawing can all those solutions or critical points be seen in concrete way (see also Eisentraunt & Günther, 1997). In engineering, the finalized form of the sketch is presented in technical drawings; these show all details of appearance, how the artifact or machine works and how it will be constructed.
Eisentraunt and Günther (1997) analyzed the kinds of external representations mechanical engineers created during their adaptation of the design task. The graphical documents (i.e., marks-on-paper) were categorized according to concreteness (e.g., idea or drawing to scale) and completeness (e.g., part or whole product). They found that all four of their subjects in study used more concrete than abstract representation and that, during the design process, the number of representations ranged from 10 to 20. Moreover, each subject showed a unique and individual pattern of problem solving. Eisentraunt and Günther (1997) concluded that the use of drawings and different types of sketches depends in particular on an individual’s style of designing.
Besides the sketching, the designer often uses and manipulates other physical tokens (i.e., prototypes, study models, samples and experiments). According to Ferguson (1992) artisans in crafts can and usually do make things directly, requiring only the materials, tools and skills needed to convert the materials into the desired artifact. Nowadays, however, particularly in the professional context, designing and manufacturing are separate. Thus the drawings and notes have become crucial in bringing ideas to external form, and especially in depicting details, so others can understand the artifact as the artisan or designer intends. Working with these varied external representations or physical models, designers are better equipped to develop, reflect and communicate ideas with others.
In the professional and actual (i.e., long-term design projects) design process, there are intimate relations between production of drawings and prototype or model-making. Models are made after drawings have been produced. The drawings serve as blueprints in construction of prototypes (Ferguson, 1992). Written qualifications for visual drawings are substantial when they are presented to other people, and it should present the all details of the product, as well as work instructions containing the information needed to produce the product (in the case where the designer is separate from the manufacturing). To conclude, visualization and all external representations serve as pivotal aspects in designing. Visualization can serve as memory-aid; it also can disclose those features not yet worked out. During the design process, different kinds of sketches and prototypes and models can be produced, with varying levels of concreteness and completeness. The nature of the sketch and the intensity of the sketching activity generally depend on the task and individual style of the designer.