Preliminary Sketching and Prototyping: Comparisons in Exploratory Design-and-build Activities

This study explores the role of sketching when designers are creating fast, preliminary prototypes during hands on design-and-build activities. Many studies have noted the value of both sketching and the building of preliminary prototypes in the early stages of the design process. In a typical design scenario, exploratory sketches are made before prototypes are fabricated. However, in certain cases, the differences in the design exploration value of a sketch and a simple, preliminary prototype may not always be clear. In this study, three conditions for a design-and-built activity were compared: a control group (allowed to freely sketch throughout), a limited sketch group (only allowed to sketch at the beginning) and a no sketch group. The study was conducted twice, using different prototyping materials each time. One focused on assembly only (an Erector set) and one that requires both part fabrication and assembly (foam core). The performance of the prototypes, the type and quality of the sketches, and the relationship between sketches and prototypes were evaluated. Results for this study suggest that fast, preliminary prototypes are equally as useful for design exploration as sketching in building simple mechanisms, though results would likely be different for more complex design tasks. INTRODUCTION Designers employ a range of tools and techniques while involved in key activities of early stage design such as generating, selecting, and evaluating concepts. Tools may be used to explore and evaluate ideas in order to drive the design process forward, including sketching of possible design concepts [1-3] and the building of prototypes of design alternatives [4-6]. In particular, the process of constructing physical prototypes of a design idea can uncover important design issues [7] that may not be apparent from a 2D representation such as a sketch. Sketching is a traditional tool for exploratory, early stage design because it is fast and requires few tools. It is valuable for capturing and communicating design ideas while preserving ambiguity and design freedom [8, 9]. The importance of sketching has been linked closely with design thinking and creativity [10]. It is often thought of its own design “language” to aid in external representation of ideas [11-14]. In contrast, the building of prototypes is usually part of the iteration and decision making process because it allows evaluation of specific aspects of design [15]. Prototypes are typically, though not always, constructed after sketching. Gerber, et al. have found that “low-fidelity prototyping allows practitioners to reframe failure as an opportunity for learning, supports a sense of forward progress, and strengthens beliefs about creative ability” [16]. Like sketching, prototyping can be thought of as residing on the continuum of the visual language of design. This paper examines a subset of prototypes, specifically fast, preliminary prototypes, which are typically constructed using materials that allow quick fabrication of parts, and/or simple assembly of parts. Industrial designers refer to such prototypes as “sketch models” in part because they grow from sketches yet they are less than a full prototype. The line demarcating a full prototype from fast, preliminary prototypes can be a blurred one. This study considers the interplay of sketching and prototyping in the design process of a design-and-build activity,