In this article, Dr. Owain Pedgely, using his unique polycarbonate sounding board for acoustic guitars as an example, explains how to develop a successful graduate design thesis.

It is the conclusion of the Working Group that it is in the best interests of scholarly endeavour and international understanding to direct attention to elucidating how the three principles - of excellence in a contribution to and knowledge of methods in a subject, tested through oral, external examination - apply where the intention of the candidate is to make a contribution as a researcher in a practice-based field.

This article makes a contribution to research methodology through the description and analysis of a Ph.D. programme undertaken at Loughborough University between 1995 and 1999 [4]. The subject matter of the programme broadly involved an investigation of industrial designers' involvement with (and concerns for) materials and manufacturing processes. The programme was built upon a theoretical position and research agenda developed and published in two papers by the Ph.D. Supervisor, Eddie Norman [5,6]. The more recent of these papers discussed knowledge, skills and values as aspects of technology, in order to establish a theoretical position in relation to technology for design. In its final section, the paper noted a concluding statement made in 1993 by Bayazit [7]: "We have to make more empirical studies on designs and designers." The paper also stated Norman's view of the priorities for design research.

• Further case studies concerning the knowledge base associated with different areas of the design field should be explored and, where possible, made evident.
• The way in which knowledge, skills and values are used by designers should be carefully documented and analysed.
• Known good practice in design pedagogy should be identified and critically reviewed.

The Ph.D. programme of concern in this article addressed the first two of these items in a particular area of the design field: the consideration of materials and manufacturing processes by industrial designers.


2. Requirements for a Ph.D.
As a graduate industrial designer, Owain Pedgley (referred to from here onwards as OP) wanted to structure his doctoral programme to include product design work that would be of direct benefit to his design portfolio. For would-be researchers whose primary expertise is in creative design work (e.g., industrial design, sculpture, engineering design), it seems only sensible that their prospective research programmes should make good use of that expertise. After all, physicist researchers do physics, chemist researchers do chemistry and so design researchers should design. However, designing artefacts is what all industrial designers do. Unless all excellent practice is to be rewarded with a Ph.D. degree, the artefact(s) and the associated design activity for a practice-based Ph.D. degree must meet additional criteria. Frayling's report suggests a similar view [op. cit.].

The researcher/academic role is best suited to those whose work or aspiration has analysis or evaluation of the creative process or product, as well as excellence in its expression, as an integral part of the thesis.

Such a view is also expressed in separate articles by Cross [8], Allison et. al. [9] and Friedman [10].

The whole point of doing research is to extract reliable knowledge from either the natural or artificial world, and to make that knowledge available to others in a re-usable form. This does not mean that works of design practices must be wholly excluded from design Ph.D.s, but it does mean that there must be reflection by the practitioner on the work, and the communication of some re-usable results from that reflection.
[8]

It is principally the accessibility of the research process and the methodologies adopted which distinguishes practical research from simply the output of creative or practical people, such as artists, designers, engineers, composers or poets. In this, the definition of research given earlier: 'systematic enquiry which is reported in a form which allows the research methods and outcomes to be accessible to others' is critical in distinguishing what may be termed research from non-research.
[9]

What is not acceptable is the situation we have seen in the context of what is labeled [sic] design research. This involves a designer showing his or her work while stating, 'This is what I have been experimenting with. Since I am a designer, this is design research'... It is the nature of the research act and the act of theorizing that defines the work of the doctorate. Under some circumstances, this may include practice, but it cannot be comprised only of practice. That is the path of the guild master, not of the doctor.
[10]

With these statements as a backdrop, in what ways can one successfully make one's own designing an integral component of a research programme? An internet discussion on this topic was initiated by OP in 1997 [11].

It would be interesting to find out in what ways people on this list have incorporated their own design work (design-_ing_ [sic] as well as designed products) into their Ph.D. studies (as opposed to conducting research where the candidate does no designing / makes reference to none of his/her design work). How have you used your own designs / designing: to demonstrate new thinking? to test new procedures? to investigate how designing takes place? Trained designers (including graduates), could benefit from some reassurance that what they have been trained in -designing- does not have to be put on one side if they choose to embark on a Ph.D. study. Responses to the above question would provide some valuable insights into how candidates can go about incorporating their own design work into a Ph.D. programme.

At the time very few responses were received but if the questions were to be posed now, three years on, the results would probably be quite different, such is the raised interest in the issues. The various ways in which a practice-based element might be incorporated into a Ph.D. programme are discussed in the final section of this article. But to conclude this section, in circumstances where research is carried out with an intention to submit the work for a higher degree, certain academic standards are expected to be upheld.

• Prior to commencing their work, students must register for a research degree with an academic institution.
• The final submission (e.g., thesis, artefact, CD-ROM, exhibition) must form a contribution to a body of knowledge.
• The contribution to knowledge must be unambiguously stated.
• Training in research methods must be demonstrated in the final submission (indicating competency to supervise subsequent research projects).

And for a Ph.D. programme that incorporates a practice-based element, at least three areas of attention need to be considered.

• The selection and development of a suitable design task.
• The selection and development of methods for recording the design activity associated with the task, in order to generate appropriate data.
• The selection and development of methods for data analysis, in order to make a contribution to knowledge.

To maintain a clear focus for this article, only the first of these three areas will be examined in detail, with some mention of the second.


3. Selection and development of a suitable design task
The original research proposal which led to OP's Ph.D. programme identified a need to understand better the links between technology (in the sense of a designer's knowledge, skills and values) and technical subjects (for example, mechanics, materials, manufacturing and ergonomics). Materials and processes were selected as the focus for the research because of their fundamental importance to product design.

In 1991, a Working Party led by Professor Jeremy Myerson analysed the technology taught on industrial design courses in the UK. The resulting report [12] showed that the practices in industrial design courses are determined through a variety of mechanisms that make use of, for example, the professional experience of staff, input from external examiners and advisory boards, and feedback from graduates. But at best, these sources provide indirect evidence of the technology currently used by practising industrial designers. The primary agenda for OP's Ph.D. was therefore to identify and discuss the knowledge, skills and values employed in present-day practices.

3.1 Objectives of the practice-based element
At the commencement of the Ph.D. programme in 1995, there was little practical advice available on how one could go about capturing design activity and build documentary evidence of how designers think and work. This situation made a long-term empirical study of professional practice an unrealistic goal. To improve upon the situation, it was decided that a primary objective of the practice-based element would be to establish effective approaches to the recording of long-term design activity. The conclusions would form a substantial proportion of the 'contribution to knowledge' in the final thesis. (A short review of the adopted methods are discussed in section 4 of this article.) Despite the methodological objective, the overriding reason for the inclusion of a practice-based element remained for the generation of data on the interactions of materials and manufacturing processes with industrial design activity.

The underpinning theoretical position for the Ph.D. programme was that technology for design could be regarded as a summation of knowledge, skills and values [5]. Much was already known about the knowledge component, in particular knowledge closely associated with science (which has to be developed and reconstructed in order to be useable by the designer, as shown, for example, by Vincenti [13] in relation to aeronautics). Far less empirical evidence and supporting discussion existed for the skills and values components of technology for design. This was surprising, given how important these components are generally regarded, especially within areas of the design field drawing upon artistic and craft sensibilities and practices.

A view was taken that design work for most consumer products could potentially yield data concerning materials, manufacturing processes and decision-making, but in order to readily expose the contribution of skills and values, a project needed to be identified for which the knowledge component (as related to science) was minimal. It was this issue which led to the selection of a polymer acoustic guitar as the design project for OP's Ph.D.. The project had originally been identified in 1993 by Norman [6].

3.2 Polymer acoustic guitars
There have been many precedents for the use of plastics in acoustic guitar bodies, most commonly the use of fibre-reinforced resins (e.g., carbon fibre, glass fibre) to create all or part of the instrument's soundbox. Several US companies have refined this technology and produced many innovative (though relatively expensive) instruments (e.g., Rainsong, Ovation Adamas, Composite Acoustics, Chrysalis). At the other end of the spectrum are injection-moulded toy instruments.

However, against a backdrop of large growth in the range of advanced polymers and plastic processing available to designers, the use of new (synthetic) materials in the body of acoustic guitars is by all accounts limited. It was within this context that the polymer acoustic guitar project was conceived. It was felt timely and worthwhile to take a new look at the use of synthetic materials in guitar construction, as a challenge to see what might be achieved with new technology (e.g., tonal qualities, opportunities for mass-manufacture, changes in appearance, reduction in craft labour and final product costs). Decisions were made on what would constitute a successful final outcome and it was decided that it could equally be (a) an instrument having qualities of tone comparable to a wooden instrument or (b) an instrument having a musical character all of its own. At no point was it an aim to imitate a particular style of wooden guitar.

Additional factors also pressed the case for the polymer acoustic guitar as a suitable project.

• Acoustic guitars on the high street are caught in a trap of visual tradition. They have very similar designs in order to conform to what people expect of a guitar. A polymer instrument could open new markets by challenging that conformity.
• Both OP and Eddie Norman were involved in their own music-making and so the personal enthusiasm, commitment and interest in the product development would be strong. This was particularly significant since the designing would inevitably be a long process.
• The development of innovative guitar technology was timely, because of the environmental issues and pressures associated with prime tonewoods.

At this point it is useful to scrutinise acoustic guitar construction further, to reveal the complexity of the issues and the nature of the design task that was faced. The modern-day classical guitar (a close relation to the steel-strung acoustic guitar) was developed empirically, largely by Antonio De Torres in the nineteenth century. One might have thought that in the pursuit of further excellence in guitar design, scientific methods would offer guitar manufacturers prized design advice. However, consider the following description of the major effort in this field made by Gibson in the late 1970s [14].

There is a relatively recent example of a major guitar-maker taking science on board - and failing to capture musicians with the new guitars. In 1977 Gibson launched the Mark Series acoustic guitars. In the promotional literature for the four new models, the 35, 53, 72 and 81, the company explained how, in the past, improvements to instrument design had come about by trial and error, and luck. "That's why Gibson chose a new method in its search for a better acoustic guitar - the scientific method". Gibson's two-year research plan involved three scientists: a professor of acoustical physics, who recorded and analysed 'voice graphs' of popular guitar designs: a chemical physicist (also director of an institute of molecular biophysics) to oversee structural design: and a professor of acoustics who devised new scientific measuring techniques and an environmental test chamber. But despite all this, the guitars did not prove popular and were soon dropped from the Gibson catalogue. The company returned to their old, proven method of trial and error (and luck), and most players would argue that they returned to making good guitars as a result. Gibson's high-profile failure deterred many makers from the scientific route.

The design of wooden guitars is clearly not easily advanced through the application of scientific data. But what advice could science provide for the design of a polymer guitar? An initial literature search revealed Dr Bernard Richardson's work at Cardiff University [15] but little else that could help. As an alternative, perhaps a polymer expert could identify the ways in which science would be able to contribute to the design of a polymer guitar?

To respond to the question, a small forerunner research project at Loughborough University conducted by Paul Gay and supervised by Dr Richard Heath was undertaken [16]. It incorporated a literature review that found polymers had yet to be categorised by their resonant characteristics (polymers are generally used to dampen sound). The review also found that sound propagation properties for timbers, let alone polymers or polymer composites, were effectively non-existent. There was even no standard test which could be used to compare material samples.

Gay's research project had the aim of learning more about the relationships between measurable mechanical properties of materials and the 'acoustic performance' of those materials. By way of experimentation and the analysis of literature, the project aimed to understand how a material may either propagate or attenuate a vibration. The main objective was to find suitable equipment and develop associated methods to quantify sound translation, and then compare the acoustic performance of different timbers and polymers. The basic experimental method employed was to impart energy at a consistent point on a thin rectangular sample, and then to measure the resultant vibration amplitude for a frequency range at points away from the original striking position. Several problems were observed with this method of which the following were the more significant.

• Sound generation in an acoustic guitar depends upon the vibration of free surfaces. Either supporting or clamping the sample meant deviating from this ideal.
• The geometry of the test pieces had a significant influence on the results obtained.
• It was extremely difficult to apply a consistent input energy into the samples.
• The deployed measuring devices (transducers and accelerometers) influenced the results significantly.

The described problems led to considerable difficulty in interpreting the results. For example, a comparison of spruce and polyester composite samples showed that for the same sample geometry, harmonics were at higher frequencies for the spruce. Even with simple sample shapes, it was difficult to identify the combination of specific properties that could be used to model this behaviour. Elastic and shear modulus, density, internal friction and Poisson's ratio were thought to be amongst the more important factors. As the behaviour could not be successfully modelled in simple rectangular samples, there was little hope of modelling a real instrument with its complexity of shape, bracing and material thickness.

Empirical studies with timber have shown that different wood types, drying, ageing, cuts, lamination, etc. have marked effects on aural properties. Polymers and their composites have a similarly large number of variables. It was clear that on the limited scientific evidence, some of the fundamental matters of materials selection and construction for a polymer acoustic guitar would be difficult to resolve.

• Would plastic materials with isotropic properties perform better than those with anisotropy? Polymers and polymer composites can have different isotropy owing to, for example, molecular or mechanical orientation, reinforcements and crystallinity. Wooden guitar components (oriented composite structures) have been empirically demonstrated to have acoustic performance dependant on grain direction.
• How would component geometry, including thickness, influence the acoustic performance of an instrument?
• How would component interactions influence sound transmission? In Gay's study [ibid.] it was felt that in time it might be possible to obtain quite a broad range of quantitative data from simple test piece shapes. However, it was evident that no software (or other means of prediction) was available to show how a vibration might be transferred in simple assemblies from one component to another, perhaps via a glue-line. From this perspective, how could the performance of a complete assembly of guitar components be predicted?

A major scientific study of polymer vibration characteristics would have to be conducted to answer these various questions. For the current concerns, however, it was clear that sources of design advice not reliant on science would be needed if a playable guitar was to be achieved within the four years of OP's Ph.D. programme.

3.3 Finalising the design project
Having deliberately chosen a design project for which little help could be expected from the world of polymer technology, there may be some readers who would expect inevitable failure. The authors were not so sceptical. (It is well-known that the steam engine would not have been invented had its designers waited for thermodynamics to emerge first.) To help steer the design and development, a collaborator for the project was secured: a world-renowned guitar designer, Rob Armstrong of Coventry, U.K. When approached, Rob Armstrong had built well over five hundred acoustic guitars, and although it would probably be difficult to articulate precisely what he knew, there was no doubt about the value of such expertise.

One of the definitions of design offered by John Chris Jones is "...the performing of a very complicated act of faith." [17] It was in this spirit that the designing was approached, coupled with the clear intention of revealing some of the complexity in the performance (Figure 1). As the astute reader probably suspects, a successful prototype instrument has been built. However, the research programme would still have had some validity without a completed product (since it was the activity of designing and not the final designed artefact that was of primary importance for the Ph.D.). In other circumstances however, an alternative view may be taken: if a final prototype has either not been achieved or has been achieved but is unsuccessful, what worth is there in the process that led to that design?


Figure 1: Paper-based designing, part of a 'very complicated act of faith'

The project reached a culmination in 1999 when the first-generation prototype was endorsed and played by the UK guitarist Gordon Giltrap. On top of this, the media attention has been extensive [e.g., 18, 19, 20, 21]. As part of the instrument's development, Loughborough University has filed patent and registered design applications and is currently pursuing commercial exploitation of the instrument's technology. The University is set to recover much of its investment if a production version of the instrument is developed. It is an interesting point that had a less innovative and less publicly well known product been selected for the Ph.D., the consequential media attention (bringing benefits to both the student and the University) would probably not have arisen. For example, would the design of a compact disc shelving system- a perfectly plausible industrial design task- have caused such a stir?



4. Selection and development of methods for recording design activity
To undertake analyses of design activity first requires the acquisition of evidence. This in turn requires the implementation of tools for rigorous recording of designers' decision-making. A workshop on 'analysing design activity', organised by the Faculty of Industrial Design Engineering at Delft University of Technology in September 1994, provided affirmation of this starting point. The papers resulting from the workshop were published in a special edition of Design Studies in April 1995 (Volume 16, Number 2). The workshop focused on the use of 'protocol analysis' (the analysis of transcript and video data of research participants talking aloud their thoughts whilst they work) as a tool for capturing and making sense of design activity. Among the conclusions was the following observation [22].

The adoption of protocol analysis as a research technique for design is an effort on the part of design methodologists to find a rigorous form for their empirical research. Protocol analysis is somewhere in the middle ground between the 'hard' experimental methods of the natural sciences and the 'weaker' purely observational methods of the social sciences. The whole of empirical research can be seen as a balancing between these, trying to lean both ways. The general feeling in the discussions at the workshop was that the balance has tipped too much to the side of rigour and 'safe' research techniques, at the expense of 'relevance' of results for design practice and education.

A drawback of protocol analysis is that to be practicable it requires the designing under study to be a relatively short exercise conducted in conditions not unlike a laboratory. The lack of realism under such conditions casts some doubt on the relevance of results to 'real world' design activity. To respond to this reservation, an initial period of design work was undertaken in OP's Ph.D. programme, with the specific intention to develop techniques for the documentation of long-term (months) of naturalistic design activity. An important part of this process was an assessment of the richness of data that could be gathered by different data collection methods. Initial findings of this assessment were published in 1997, along with trial results of a 'diary of designing' data collection method developed by OP to systematically document his work on the guitar project [23; Figure 2]. Some of the conclusions of the 1997 paper were as follows.

Based on trials, diaries on a focused topic of designing have been shown to provide usable information where industrial designers' approaches to their work rather than intricate trains of thought are of interest to the designer... The content of diaries is suitable for the analysis, in conjunction with development sheets, of occurrences, patterns, trends, peculiarities, expectations and surprises. It is conceded that documenting design activity in such a detailed manner has drawbacks.

1. It requires the production of some documents which are not normally expected of a designer; the production of these documents may be considered obtrusive by some designers.
2. Diaries rely on honesty; the completeness and accuracy of accounts given in this way will always be limited.
   
   Figure 2: Production of a diary of designing, overlaid onto an A3 sketch sheet
   
   Once the diary method had been refined it was then used to gain documentary evidence of how materials and manufacturing processes were worked into the polymer acoustic guitar. The resultant diary described the design activity over the months between drafting of the brief to delivery of a first-generation prototype. In the Ph.D. thesis, the results from the guitar project were triangulated against evidence from interviews with professional and undergraduate designers and against evidence recorded in literature.
   
   
   
   5. Conclusions
   The practice-based Ph.D. programme outlined in this article involved aspects of design technology, design praxiology, design language, design epistemology and design values in practical decision-making. It was derived directly from the research policy and strategic objectives of the Department of Design and Technology at Loughborough University and was built upon research previously undertaken in the Department. The research was cross-disciplinary and integrative in nature, something which was, again, central to the Department's activities. It is anticipated that the followed programme will lead to a model for subsequent practice-based Ph.D. and M.Phil. degree programmes in the Department of Design and Technology, bringing the following benefits to the researcher.

• The opportunity to advance one's capabilities.
• The opportunity to immerse oneself in a subject area that one finds stimulating.
  
• The opportunity to give back something new to a community that has given much.
• The generation of investigative and critique skills that have wide application in professional and everyday life.
• First-hand experience of the discipline and commitment required to manage and undertake an extensive project.

In concluding his editorial on analysing design activity, Dorst wrote as follows [22].

The overall picture of empirical design research in the near future is that of larger research projects, in which multidisciplinary teams of researchers work together on analysing more complex and realistic design tasks. Techniques like participant observation and interviews can be used for analysing long-term processes. Protocol analysis can take its place among the more detailed techniques for studying short-term processes or some especially significant turns in the design saga.

A similar statement could easily be constructed concerning the diary data collection methods explored in OP's doctoral research. Particular techniques will eventually find their place in a grander scheme. There is, however, a long way to go before the design research field matures to the point where the writing of a comprehensive guide to design research methodology could be contemplated. Many small-scale contributions are needed in order to develop a consensus on the benefits of alternative approaches to generating, acquiring, recording and analysing ways of knowing.

With regard to content, a practice-based Ph.D. submission in design must contain at its heart a contribution to knowledge as well as design excellence. However, the precise part played by the practice-based element can differ considerably between programmes, depending on the specific research agenda. Let us consider two research programmes with quite different aims and objectives, but both drawing upon the integration of the researcher's practical design work. There will be other kinds of research programme that require (or would do well to include) a practice-based element, but the following are seen as especially useful models.

5.1 Programme one: advancement of the design of a particular artefact
The outcome of this kind of programme is likely to be an innovative product having novel and advanced design specifications. The product will be an embodiment of new technology, principles or design methods and, as such, will contribute to what is known about how that kind of product can be designed and how it can operate. For example, the product might exhibit new features (such as ingenious design details and cutting-edge material finishes) and is likely to offer clear benefits to either users or manufacturers. A target audience for such research will be practising designers, who will be able to make use of the 'road tested' new approaches and technology. An important consideration for this kind of design project is the 'weight' or significance of the artefact: will the project involve minor tweaks to an existing design (a relatively weak proposal) or will it involve a major new product opening (a relatively strong proposal)? Similarly, will the project be carried through to a working prototype (a relatively strong proposal) or will it be limited to a conceptual stage (a relatively weak proposal)? The significance can be measured by:

• the standing and reputation of any commissioning or sponsoring organisation or company;
• the places in which the product receives attention (e.g., exhibitions, media, public spotlight, publications);
• offers from, or agreements with, third parties to undertake development work;
• requests for further design commissions based on the strength of the research outcomes.

For a designed artefact to be considered in the UK Research Assessment Exercise, it must have reached a stage of development where the significance and evaluation of prototypes has been made [24]. It is insufficient for the artefact to be still 'on the drawing board' and ideally the product will have gone into production.

It will be important in this first kind of research programme to thoroughly document the steps that have resulted in the final designed outcome. In the final degree submission, both the specification of the product and the path to its conception will need to be reported and reflected upon. Where possible, the success and impact of the final artefact (and of the preceding design process) should be measured. In this way, the adequacy of the technology, principles, methods and ideas that were employed in the designing can be demonstrated. Without such evaluation, how can one determine whether one has achieved one's research aim?

An example of this first kind of practice-based research is work on communication devices for people with severe disabilities, carried out by Jon Allen whilst a research student at Loughborough University [25]. Within Allen's work, designing is used as a mode of enquiry that resembles 'action research', a methodology that has long been used in humanities research. Research questions become apparent through designing (i.e., through the investigative techniques that are a characteristic of design activity) and can be addressed through designing (i.e., through the engagement of intentional reactive responses that are a characteristic of design activity). Hence, as with action research, the researcher is participant (or intervenes) in the situation under study, to make some desired or anticipated events happen or circumstances avail. One example is in the negotiation of the specification of a product with a potential user and in the subsequent setting of direction for further design work. The potential for design activity to serve as a mode of research enquiry has been expressed before.

Design... is a product of imaginative thinking and problem-solving, and is often the means by which new information or understanding can be discovered and used.
[26]

The activities of creation and invention are expressed in the ability to relocate the bounds imposed in other systems of reference, thus creating the new that which until now has not been thought of and indeed seemed unthinkable.
[27]

As with action research, careful documentation of the intervention into the situation needs to be made. For example: what purpose was the intervention intended to serve?; how can the intervention be described?; what were the outcomes and benefits of the intervention (from the perspectives of all the people involved)? Answers to these questions will form a "...methodological account that involves autobiographical details outlining the researcher's involvement in the social situation..." [28]


5.2 Programme two: advancement in understanding of designers' decision-making
This second kind of programme places the activity of designing at the centre of attention and is a fitting description of the kind of work in OP's Ph.D. The researcher's designing will be used as a case study and the creation of a designed artefact is in essence just a means to a more pressing end: finding out at macroscopic and microscopic levels how designers think and operate in their current practices. The researcher's own designing will provide a source of primary data. However, there are several methodological quandaries to grasp with this use of the practical design element.

• How can one objectively analyse one's own designing?
• Is one's designing sufficient in itself to form the data for a research project (particularly with respect to generalisation)?
• The concerns of 'weight' and significance of the design outcome are shared with the first kind of research programme.

The approach adopted for OP's Ph.D., a focused analysis of decision-making (relatively independent of the product under design), is but one approach among many.


References

1. ARCHER B. (1999), personal communication via Professor P H Roberts
2. BUCHANAN R., DOORDAN D., JUSTICE L. & MARGOLIN V. (eds.) (1999), Doctoral Education in Design: proceedings of the Ohio Conference, Pittsburgh: The School of Design, Carnegie Mellon University
3. FRAYLING C. (chair.) (1997), Practice-Based Doctorates in the Creative and Performing Arts and Design, Warwick: UK Council for Graduate Education/CEDAR University of Warwick
4. PEDGLEY O. (1999), 'Industrial designers' attention to materials and manufacturing processes: analyses at macroscopic and microscopic levels', Ph.D. thesis, Department of Design and Technology, Loughborough University
5. NORMAN E. (1998), 'The nature of technology for design', International Journal of Technology and Design Education, Vol.8, No.1, pp.67-87
6. NORMAN E. (1993), 'Science for design', Physics Education, No.28, pp.301-306
7. BAYAZIT N. (1993), 'Designing: design knowledge: design research: related sciences', in deVries M., Cross N., & Grant D. (eds.), Design Methodology and Relationships with Science, Dordrecht: Kluwer Academic, pp.120-136
8. CROSS N. (1998), editorial, Design Studies, Vol.19, No1, p.2
9. ALLISON B., OWEN A., ROTHWELL A., O'SULLIVAN T., SAUNDERS C. & RICE J. (1996), Research Skills For Students, London: Kogan Page, p.21
10. FRIEDMAN K. <ken.friedman@bi.no> (1997), 'Doing one's own design work in a PhD', 2 October 1997, posting to <drs@mailbase.ac.uk> (not archived)
11. PEDGLEY O. <o.f.pedgley@lboro.ac.uk> (1997), 'Doing one's own design work in a PhD', 2 October 1997, posting to <drs@mailbase.ac.uk> (not archived)
12. MYERSON J. (1991), Technological Change and Industrial Design Education, London: C.N.A.A.
13. VINCENTI W. (1990), What Engineers Know and How They Know It: analytical studies from aeronautical history, London: The John Hopkins University Press
14. BACON T. (1991), The Ultimate Guitar Book, London: Dorling Kindersley, p.10
15. RICHARDSON B. (1992), 'Vibrations of stringed musical instruments', University of Wales Review
16. GAY P. (1993), 'Vibration testing of materials', Mechanical & Materials Engineering final year project, Department of Mechanical Engineering, Loughborough University of Technology
17. JONES J. (1980), Design Methods: seeds of human futures, Chichester: John Wiley, p.3 (first published 1970)
18. GRAHAM-ROWE D. (1999), 'Taking the guilt out of rock-and-roll', New Scientist, No.2213, p.23 (archived at: <http://www.newscientist.com/ns/19991120/newsstory13.html>) (25.03.00)
19. LINGARD P. (1999), television report, BBC News 24 (archived at: <http://news.bbc.co.uk/olmedia/565000/video/_565749_guitar0700_vi.ram>) (25.03.00)
20. MIERAS M. (2000), 'Gitaar van plastic', InterMediair, 13 January, p.95
21. 13TH FRET GUITAR FORUM (2000), <http://206.170.59.22/wwwboard/wwwboard.html> (25.03.00)
22. DORST K. (1995), 'Analysing design activity: new directions in protocol analysis', Design Studies, Vol.16, No.2, pp.139-142
23. PEDGLEY O. (1997), 'Towards a method for documenting industrial design activity from the designer's perspective' in Smith J. (ed.), IDATER97, Loughborough: Department of Design and Technology, Loughborough University, pp.217-222
24. WOOLLEY M. (1998), address given at the one-day seminar 'Designing Design Research 2', De Montfort University, Leicester
25. ALLEN J. (2000), Ph.D. thesis (in preparation)
26. MORRISON J. & TWYFORD J. (1994), Design: capability and awareness, Harlow: Longman, p.65
27. MANZINI E. (1986), The Material Of Invention, Milan: Arcadia, p.17
28. BURGESS R. (1981), 'Keeping a research diary', Cambridge Journal of Education, Vol.11, No.1, p.75-83


About the authors
The authors are based at Loughborough University, England. Eddie Norman is a senior lecturer within the Department of Design and Technology; Dr Richard Heath is a senior lecturer within the Institute of Polymer Technology and Materials Engineering. Dr Owain Pedgley is currently working as a freelance industrial designer, prior to taking a research post with the Sports Science, Engineering and Technology Network at Sheffield University, England. For queries about undertaking design research at Loughborough University, please contact Dr Diane Gyi (d.e.gyi@lboro.ac.uk). Further information on the polymer acoustic guitar can be found at the following URL.

www.lboro.ac.uk/departments/cd/docs_dandt/research/dr/polyguitar/index.html

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