Why sketching? What is it? And, why is it important to design?

Design as a Process

A conventional approach to understanding design and one that is often cited is from the classic book, Engineering Design Methods by Nigel Cross who subdivides the process as a series of linear, yet distinct activities; from concept to development to detail design.

Enter a caption (optional)

Of course, these sections may be thought of as iterative; not as linear as the model depicted in Figure 1 may suggest. Indeed, a process of design will often shift and iterate between and among these sections (as indicated through the returning, curvilinear arrows).

However, if we think of design as a sequence of iterative phases that progress towards final production, we are then able to identify an open or fuzzy phase of design. In this we contrast a divergent conceptual design ideation with a more convergent, specific and detailed design phase. We do this as much to contrast the different aims of design at these different phases of the process, as to highlight the kinds of design work involved or tools used at any given stage.

Sketching Concept

Various tools of expressive design representation are utilized as part of the design process, comprising of a wide variety of media to produce sketches, drawings, models and prototypes. At a conceptual, or divergent and open end of design, idea sketches, study sketches, usability and memory sketches are often used in order for the designer or design team to express, explore and communicate design intentions to other team members.

This kind of sketching can be described as concept sketching. However, in the context of our discussion of the why of sketching to follow, we can turn this around and instead describe sketching concept. In this way we now focus attention on the designer as a user of the tool of sketching rather than the sketch itself. This then has the potential to provide a far richer space to examine the influence and implications of sketching as critical tool for design. This is because it then more directly points towards the kinds of reasoning involved and required to create "marks on paper" during the ideation phase.

As we move forward in a process of design, from conceptual design ideation through development design, other kinds of design representations are often used by the designer to develop, explore, propose and communicate design intentions. The kinds of sketches that are used in this phase include sketch rendering and explanation sketches. These high fidelity sketches are often more than ambiguous sketches employed during the earlier phases of the design process. An example of a high fidelity representation is the use of inspirational sketches to convey design intention and the emotional reasoning to other stakeholders and clients.

Taxonomy of Design Sketches

As design progresses, the kinds of representations employed to communicate the designer's intentions to others also move towards an even higher level of detail and fidelity. As such, the kind of sketching, the character of sketching, has a relationship to the stage in design that the designer or design team is engaged with. In this way sketching may be categorized within taxonomy along the dimensions of a classification system that uses levels of detail, fidelity and stage to categorize various sketches and illustrations.

Taxonomy of design sketches, drawings and illustrations (derived from Pei et al)

The focus on the designer as sketcher, however, is reflected in the four taxons of explorative, persuasive, explanatory and prescriptive sketches that then see sketching through the lens of purpose of output rather than referencing the inherent characteristics of the different sketches themselves or the stage which they are used.

Looking at the kinds of illustrations presented above, it becomes apparent that ambiguous and casual sketches are most prolific during the explorative phase of conceptual design ideation. This addresses the first of our questions: Sketching is a critical way through which the designer expresses and explores ideas during concept design ideation.

Thus, we must now attempt to address the reasons why sketch ability appear so critical to conceptual design. One way is to understand the kinds of reasoning required to engage in generative conceptual ideation. We may then be better placed to consider the kinds of reasoning required against sketching's role and use as driver for ideation.

Conceptual Ideation as Reasoning between Problem and Solution

Design ideation appears to require a particular type of generative thinking. One way to define this kind of thinking is apposition reasoning. Appositional reasoning may be described as reasoning between a problem and the solution where an understanding of the problem emerges through attempts made at its resolution. The designer concurrently attempts to understand the design problem and possible issues associated with it (i.e. user needs, the context and scenario of use, functional and material choices, possibilities for manufacture etc), while at the same time moving between problem definition and solution ideation to propose, suggest, select and finally develop potential solution candidates. Thus, conceptual ideation may be thought of as an iterative (between problems and solutions) and reflective activity (evaluation of the potential of solution candidates) in which design solutions are assessed and evaluated against an emerging understanding of the design problem.

From this perspective, conceptual design ideation can be thought as a tension between an emerging definition of the design problem, and the proposition of and reflection upon potential solution ideas. That is, the problem is defined through the proposition and reflection upon solution attempts which then iteratively provide opportunities for a greater definition of the original design problem. This process continues until a most appropriate solution is identified, or until time or resources run out.

In a recent study at the dpr.lab, a number of design protocols were conducted to compare the ideation activities of designers and non-designers, who were required to respond to a typically ill-defined problem. In this case, the participants were asked to identify a design direction for a sports watch for young people.

The resulting videos of conceptual design work were classified between problem and solution driven, whereupon it was found that the non-designers spent significantly more time in problem-focused work than the design participants. In contrast design participants engaged significantly more time in generative conceptual ideation and more frequently transited between attempts to define the design problem and explore the possibilities of solution candidates.

Interestingly, the design participants' extended time in solution ideation was seen to be driven by, or at least facilitated through, an ability to sketch. In contrast, the non-design participants spent a greater amount of time in naming particular items to focus upon within the problem space, drawing heavily upon written notes and annotations. Thus, the design participants' conceptual ideation work was very much sketch-driven, whereas the non-design participants tended to be very limited in their sketch work, preferring to offer notes and suggestions related to a definition of the problem.

So, in terms of apposition reasoning's role during conceptual ideation, we may say the design participants spent significantly more time engaging with sketch-driven, generative ideation, compared to those with little or no design ability. And that Their ability to employ sketching as means to identify, propose, and express possible solution candidates given a developing understanding of the design problem, was key to the generation of ideas and establishment of a design direction.

In contrast, when we looked at the same protocol for the non-design participants, their work was dominated by defining the problem. That is, it was dominated by attempts to express the problem, to get a stronger understanding of the issue related to it, but with far less time spent in the generative proposition of and reflection upon potential solution candidates.

This was the key significant difference between the design and the non-design participants. And it suggests that this is indicative of the ways that sketching ability or a lack thereof, inhibited appositional bridge building between the design problem and generative solution ideation.

Sketching is a critical way through which the designer expresses and explores ideas during concept design ideation.

This then appears to indicate how, through sketching, the designer is in a better position to explore potential solutions given a developing understanding of the design problem, facilitated through generative attempts at its resolution. Whereas non-designers tended to become stuck in problem definition, with little opportunity for appositional bridge-building between problem definition and the assessment of solution attempts based upon an emergent understanding of the design problem.

That is, the act of sketching supports the ability to ideate and to develop an emergent understanding of the design problem. To then employ this understanding in the evaluation of solution candidates during generative ideation appears critical to the phase of conceptual design itself. Thus sketching, in its provision of a means to propose and develop potential solution candidates, while concurrently providing opportunities to scope and (re)define the design problem, appears to be the reason for the sketch's continued and ubiquitous use during design ideation.

Finally, returning to the questions posed at the beginning of our article, we may say that sketching is a critical part of conceptual design due to its ability to provide opportunities to approximate solution ideas that are both assessed for their suitability in terms of an emergent understanding of the design problem, and concurrently contribute to such an understanding. As such, it is only through the representation of solutions that are able to approximate such things as form, design aesthetic, use and function that the designer is able to engage the kinds of appositional bridge-building required during conceptual design. This is why sketching acts as an important scaffold for reasoning between design problems and their potential solutions. Taking this further, we take the position that it is only through sketching that the designer is able to truly and effectively engage in the act of conceptual design ideation.

And so, the reason for sketching's continued and ubiquitous relationship to design, we would suggest, is its fundamental ability to provide for the kinds of generative reasoning so critical to design.

That is to say, to sketch is to design….

Co-authored by James Self (Design School, UNIST, Korea) and Eujin Pei (Department of Design, Brunel, UK). The above article is adapted from a conference presentation that was first made at iasdr2015 (International Association of Societies of Design Research), Brisbane, Australia.