CAD versus Sketching

This is the first article in an ongoing series by Dr. James Self in which he explores designers’ approaches and tools in support of a thoughtful, reflective design activity.

CAD vs. Sketching, Why Ask? ·

A continuing issue in industrial design education is when to allow students to move from sketch work to 3D CAD modelling during studio practice—or whether to let them use CAD at all! I’ve heard of first year undergraduate modules where students are ‘banned’ from the use of CAD in an attempt to encourage sketchbook work and more explorative conceptual design practice. In my view this approach is somewhat draconian and does little to deal with the underlying reasons that attract less experienced designers to the comparative certainty of 3D CAD.

Instead of setting constraints or limitations to dictate where and under what circumstances design tools must be used, design education needs to provide opportunities for young designers to reflect upon the nature of their own design activity and how this informs their use of design tools. Design students should consider the bigger picture that constitutes the various requirements of a design process in order to think about how tool use locates within and is informed by a requirement to design. This awareness will then provide opportunities for students to make more informed decisions when working with design tools; to be more critical in their use of CAD tools and more confident in their own sketching abilities.

My own research has explored the increasing variety of tools the industrial designer has at their disposal to support the development and communication of design intentions. Findings indicate that sketching continues to underpin design activity. Professional experience also influences the use of sketching in support of design activity. Less experienced design students tend to lack confidence in their sketch ability and they find the dynamic, unconstrained medium at odds with an approach to design activity that errs towards fixation and attachment to concept.

Figure 1: Design sketches used to support explorative design activity. Courtesy of Michael DiTullo

As part of my research I visited practicing designers at their places of work and interviewed them about their use of design tools. Interestingly, the designers often juxtaposed the affordance of sketching against the limitations of 3D CAD tools. Like many in design education, practitioners stressed the explorative, divergent affordance of sketching over the more constrained convergent nature of CAD. Of course they understood the value of CAD, but spoke of a concern for the ways it may limit student creativity, ‘a student’s design being too influenced by the constraints of this or that software.’

Of course, when used to support design activity, both sketching and CAD tools have the ability to complement one another in a process that has at its heart the representation and communication of design intent. Rather than limiting the use of a given tool, design education must provide opportunities for students to consider the relationship between their use of a given tool, the tool’s possible influence on their own design activity and how tool use is located within and informed by the wider requirements and responsibilities of the design process. Much criticism has been leveled at the inability of CAD to support the kinds of explorative design activity required for conceptualisation. There can be no doubt that the tool-in-hand has an influence on the character of the design representation. However, it is also true that a tool is only a tool insofar as it is used as such by the tool-user. In turn, the user is motivated by their own perception of the purpose of tool use. For students to make best use of the availability of an ever-increasing variety of conventional, digital and hybrid design tools, they require an understanding of tool use within a context of the dynamic requirements of the process of industrial design.

Figure 2: Like chess, CAD can be described as a process of ‘moves’, defined and constrained by the system. Courtesy of Michael DiTullo

Experienced designers know this and tend to take a process-first approach to the use of design tools. They think more about what is required in terms of the design process; stakeholder expectations; budget; communication of intent: from explorative, divergent conceptualisation to more constrained, convergent specification. In short, they draw upon a wealth of knowledge and past experience to guide their approach to design activity and tool use.By contrast, my research suggests the less experienced student of design can be both reassured by the command-based affordances of CAD and dazzled by its ability to create slick, glossy images. A problem with this tool-first approach is that the designer becomes more restricted by what is achievable within the tool’s constraints. The objective of design activity and the purpose of tool use shifts away from thoughts of the requirements of design practice towards the production of the CAD model as the motivation for design activity. This results in the, “This is what I did at the weekend” CAD model. “Doesn’t it look good?”

Rather than design activity and tool use locating within and informed by a wider design process, the emphasis and motivation for design becomes design embodiment itself. The design embodiment becomes the outcome of design activity and the driving motivation for the purposeful use of the design tool.

It may look good, but is it good design?

After my first few trips to design studios in and around London and the South East of England, it soon became apparent that industrial design practitioners were most interested in and motivated to talk about the differences between two design tools: hand sketch and 3D CAD. This polarisation centered on the alignment of CAD with a more convergent, generic way of working that resulted in the constrained representation of design ideas. This contrasted with a perception of hand sketching as supporting a more divergent, explorative design activity able to provide insight into design thinking and ability.

Figure 3: Concept sketch supporting explorative design activity. Courtesy of Michael Ditullo

Evidence of this dichotomy can be seen in discussion of tools within the design research community. Brian Lawson, an experienced practitioner and academic, describes the use of CAD tools as a halted, clumsy interaction when compared with the flowing, more reflective process often seen when observing the sketcher at work.

A search through the discussion forums of Core77 reveals comments by those that see sketching as something of a holy grail of design abilities; the ‘analogue dreams’ (to borrow a phrase) camp. Sketch-A-Day, a popular weblog where sketch work is uploaded and discussed, is an example of the outstanding skills these expert sketchers have. And then there are those that might somewhat derogatorily be termed ‘CAD junkies’. These designers speak fondly and with some pride of losing all track of time and space while engaged in marathon CAD sessions; the end result of which are stunningly slick digital embodiments of their conceptual ideas. Two very different embodiments of design intent, the result of two very different design tools.

This is of course true. The tool will have an influence on the design representation and the nature of design activity. This distinction is, however, somewhat artificial: it fails to take into account the designer’s skills, experiences and understanding of the activity as an influence on the ways the tool is used. An awareness of the ways in which various tools best support the dynamic requirements of the design process will inform the character of design activity. This awareness of and engagement with the various requirements of the design process, influence the designer’s approach to design activity, choice and use of design tools.

A tool is only a tool insofar as it is used as such to achieve the purpose of an activity.

Returning to my own research, the experienced designers seemed more inclined to take a holistic approach to their design activity and use of tools. Those with experience of practice possess a stronger awareness of tool use as located within and informed by the requirements of the design process. They understood how tools may be best deployed to support this process.

In contrast, design students tend to take a more constrained and fixated approach to their design activity. Their use of CAD tools only compounded a pre-existing tendency towards attachment to concept and fixation. This approach influences the ways in which students approached design activity and tool use. A tendency to fixate reflects the students’ lack of confidence in their own design ability derived from a limited understanding of why and how design tools are used.

Design education needs to foster confidence in less experienced designers. One way this may be achieved is to provide students with greater awareness of the character of design tools, their strengths and limitations. This awareness would help them better understand the role tools play as they are used in support of the design process as well as providing students with opportunities to reflect upon their own approaches to design activity and tool use. This awareness will come from opportunities to use tools in studio work. However, knowledge must also be developed through an education that describes and makes more explicit the relationships between tool, tool user and context of use.

Merely stating the benefits of one tool over another is not enough.

With these aims, my research has tried to develop knowledge that can be used in teaching, alongside studio work, as a way to help student designers to understand and critically analyse their use of design tools.

More from Dr. James Self:
» CAD vs. Sketching, Why Ask?
» To Design Is to Understand Uncertainty
» Tools of Design Representation & Conceptual Design Practices


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