Tthe he Enterprise���D encounters a starship crewed by an alien race with whom Captain Picard and company cannot communicate despite omnipotence of their universal translator1. Eventually they dis- cover that this race communicates entirely by reference to historical anec- dotes or shared myths. The Tamarians can express in a few words a com- plex concept like ���two strangers overcome their differences in the face of great peril and are friends ever after���, while conjuring up a rich picture of the emotions involved in the adventure. However it takes them equally long to convey a simple concept such as ���give me a knife���, by referring to a story of a man who opened his arms in front of a town wall and was given something. In an ethnographic study of the knitwear design process we have observed an almost equal reliance on shared cultural references to express design 1 Star Trek: The Next Gener- ation Series 5 Episode 2 ���Dar- mok���, first broadcast in the week of 30 September 1991 www.elsevier.com/locate/destud 0142-694X/00 $ - see front matter Design Studies 21 (2000) 523���538 PII: S0142-694X(00)00022-3 523 ��� 2000 Elsevier Science Ltd All rights reserved Printed in Great Britain Sources of inspiration: a language of design Claudia Eckert, Engineering Design Centre, Engineering Department, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ, UK Martin Stacey, Department of Computer and Information Sciences, De Montfort University, Milton Keynes, UK Sources of inspiration play an important role in the design process, both in defining the context for new designs and in informing the creation of individual designs. Previous designs and other sources of ideas furnish a vocabulary both for thinking about new designs and for describing designs to others. In a study of knitwear design, a process in which the use of sources of inspiration is explicitly acknowledged, we have observed that designers communicate with each other about new designs, styles and moods, largely by reference to the sources of their ideas. In this paper we discuss why this style of communication is so important, and what information it is used to convey. We view it as the use of a language to describe regions in the space of possible designs. ��� 2000 Elsevier Science Ltd. All rights reserved Keywords: sources of inspiration, design precedents, communication, collaborative design, knitwear

2 Eckert, C M Intelligent sup- port for knitwear design PhD the- sis, Department of Design and Innovation, The Open University, Milton Keynes, UK (1997) 3 Eckert, C M ���Managing effec- tive communication in knitwear design��� Design Journal Vol 2 No 3 (1999) pp 29���41 4 Stacey, M K, Eckert, C M and McFadzean, J ���Sketch Interpretation in design com- munication��� Proceedings, 12th International Conference on Engineering Design Vol 1 Tech- nical University of Munich, Mun- ich, Germany (1999) pp 923���928 5 Eckert C M and Clarkson P J ���Customisation and change processes in complex engineer- ing��� Cambridge University Engin- eering Department technical report CUED/C���EDC/TR88 (2000) 6 Walker, D J with Cross, N G An introduction to design (Open University Course T263 Design: Processes and Products, Unit 1) The Open University Press, Mil- ton Keynes (1983) 7 Eckert, C M, Stacey, M K and Clarkson, P J ���Algorithms and inspirations: creative reuse of design experience��� in Pro- ceedings, Greenwich 2000 Inter- national Symposium: Digital Cre- ativity, University of Greenwich, London (2000) pp 1���10 ideas2,3. Knitwear designers talking among themselves describe designs almost exclusively in terms of combinations and modifications of design elements that they refer to either by category labels or by their origins��� in other designs, or in other objects or images. Their words can only be understood correctly by people who know what the sources of their design ideas are. Often the referents of the designers��� descriptions are nowhere to be seen, but are simply part of the designers��� shared cultural experience. While the sketches they create to communicate designs are intended to be context���independent, the recipients��� interpretations depend on their under- standing of categories of design elements4. Knitwear designers��� communi- cation of their designs shares many characteristics of the Tamarian langu- age: complex concepts can be expressed concisely by reference to sources of inspiration, but many simple things cannot be made explicit. We have also observed very similar communication by reference in a study of heli- copter design, a branch of engineering with interesting similarities to knit- ting5. This paper seeks to describe and explain this phenomenon. Why is com- munication by reference to examples so pervasive in knitwear design? What can and cannot be said in a language of examples? When is it an effective means of communicating designs? What happens when people don���t share the same stock of reference points? 1 Sources of inspiration Almost all design proceeds by transforming, combining and adapting elements of previous designs, as well as elements and aspects of other objects, images and phenomena. Everything can be a source of inspiration to a designer. ���A good designer is inspired by everything��� is a frequent quote one hears from knitwear designers as an answer to the question what makes a creative designer. Designers use a variety of types of source: comparable designs (for knitwear designers, other knitted garments) other types of design (for knitwear designers, typically textiles and other decorat- ive products) images and works of art and objects and phenomena from nature and everyday life (such as the rhubarb leaves that lead Ove Arup to the design for the Kingsgate footbridge in Durham, England6). Real physically present objects reveal more details and carry information about manufacturing processes while images of objects already have some interpretation attached to them in the way they have been created, for example in the light in which objects are depicted, or the context created by the objects or people with whom they are displayed. We use the term source of inspiration for all conscious uses of previous designs and other objects and images in a design process7. It subsumes 524 Design Studies Vol 21 No 5 September 2000

8 Goldschmidt, G ���Creative architectural design: reference versus precedence��� Journal of Architecture and Planning Research Vol 15 (1998) pp 258���270 9 Alexander, C, Ishikawa, S, Silverstein M, with Jacobson, M, Fiksdahl-King, I and Angel, S A Pattern Language Oxford University Press, New York, NY (1977) 10 Darke, J ���The primary gen- erator and the design process��� Design Studies Vol 1 (1979) pp 36���44 11 Eckert, C M, Cross, N G and Johnson J H ���Overcoming communication difficulties in the design process by intelligent support for conceptual design��� Design Studies Vol 21 (2000) pp 99���112 12 Eckert, C M ���Design inspi- ration and design performance��� in Proceedings, 78th World Con- ference of the Textile Institute Vol 1, Textile Institute, Thessa- loniki, Greece (1997) pp 369��� 387 13 Eckert, C M and Stacey, M K ���Adaptation of sources of inspi- ration in knitwear design��� Cam- bridge University Engineering Department technical report CUED/C���EDC/TR80 (1999) narrower terms for specific uses of idea sources in design: starting design���the design that is modified to generate a new design precedent��� in architecture a culturally approved building that lends authority to new designs based on it8 reuse���the deployment of an existing component in a new context pattern���the manifestation of a solution principle9 and primary generator���a salient and explicit feature of the problem which shapes the design10. Sources of inspiration play a number of important roles in design thinking, as definitions of context, triggers for idea gener- ation, and as anchors for structuring designers��� mental representations of designs. 2 Knitwear design: a case study Our empirical study of the knitwear industry, carried out over seven years in more than 25 companies in Britain, Germany and Italy, has focused on (1) communication in design teams2,3 and how this can be facilitated by computer support2,11 and (2) the use of sources of inspiration throughout the knitwear design process12,13. While it is simple enough to be under- stood, knitwear design shares many characteristics of complex engineering projects many ubiquitous phenomena are especially salient and clearcut in knitwear design. Complexity arises from the interactions between the inherent limitations of knitted structures, material properties, manufactur- ing constraints, market pressures and aesthetic considerations. Knitwear is created by multidisciplinary teams, and problems arise from failures of communication between team members. The product is highly dependent on the context created by other designs and cultural and technological developments. The role of sources of inspiration is recognized and openly acknowledged in the knitwear industry, where they have two fundamentally different but connected functions. (1) They define the context in which new designs are created. By looking at garments and other sources of inspiration, and learn- ing what their competitors are doing, designers define the regions of design space into which their own designs should fit. The challenge is to select fashions, and locations within the envelope of each fashion, that fit their customers��� self-images, or to create distinctive products by stretching the envelope without breaking out of it (and thus appearing odd or tasteless)��� see Figure 1. Fashion as we see it in shops emerges through many designers using the same objects as inspirations according to forecast trends and the lead given by catwalk designers. (2) Sources of inspiration inform the cre- ation of individual new designs, which are adapted from one or more sources of inspiration. Designers employ a number of adaptation strategies, in which the synthesis of a new design is either triggered by the source, or the designers select a source based on a plan for their design13. Sources of inspiration: a language of design 525