1. Supporting Reinterpretation in Computer-Aided Conceptual Design Iestyn Jowers University of Leeds, UK Miquel Prats The Open University, UK Sungwoo Lim Strathclyde University, UK Alison McKay University of Leeds, UK Steve Garner The Open University, UK Scott Chase Strathclyde University, UK

2. Outline 1.Background 2.Sketching Studies 3.Shape Grammars 4.Shape Synthesis 5. Further Work

3. 1. Background School of Mechanical Engineering The Design Group Department of Architecture http://www.engineering.leeds.ac.uk/dssg/

4. 1. Background http://www.engineering.leeds.ac.uk/dssg/ Despite the widespread use of CAD systems in visual design it is generally accepted that such systems do not adequately support the early explorative stages of the design process Computational support of the act of designing requires understanding of how designers create design shapes

5. 2. Sketching Studies identified patterns and associations that designers see in their sketches e.g. Suwa and Tversky (1997) suggested links between the cognitive processes of designers and the shapes that they recognise and manipulate while sketching e.g. Lawson (2006) Previous studies of designers sketching have: We are concerned with understanding the mechanics of sketching, so that they can computationally supported.

6. 2. Sketching Studies  8 industrial designers and 6 architects took part in this study  Participants undertook three tasks Learn about segmentation Task 1 3 minutes each Task 2 Learn about (re)interpretation Industrial designers: Lemon squeezer Architects: Building 10 minutes Task 3 Industrial designers: Kettle Architects: Building Learn about design networks 14 minutes

7. 2.i Data Collection The actions of the participants were video recorded and their pen strokes were captured using a tablet input device At the end of the tasks participants were asked to elaborate on the interpretations and manipulations of their sketches

8. 2.ii Observations Interpreted as a component of the lemon squeezer Interpreted as side view Interpreted as top view The majority of participants had more than one interpretation of the initial design during the design process

9. 2.iii Analysis participant 2 participant 3 participant 4 participant 5 participant 1 Capture shape transformations via shape rules …

10. 2.iii Analysis participant 1

11. 2.iii Analysis Classification of general shape rules

12. 2.iii Analysis Frequency of use of general shape rules Capture shape transform- ations in sketches via general shape rules

13. 3. Shape Grammars Different interpretations of a shape: Formalised and manipulated with shape rules: e.g.

14. 3. Shape Grammars … and generates shapes within design networks: e.g. A shape grammar consists of an initial shape and a set of shape rules… e.g.

15. 3. Shape Grammars Shape grammars can be used to:  Analyse existing design languages  Create new design languages

16. 3. Shape Grammars Shape grammars can be used to:  Analyse existing design languages  Create new design languages Palladio Grammar: Generates villa plans in the style of Andrea Palladio (Stiny and Mitchell 1978) Buick Grammar: Generates car front ends in the Buick style (McCormack et al. 2004)

17. 3. Shape Grammars Shape grammars can be used to:  Analyse existing design languages  Create new design languages (?)

18. 4. Shape Synthesis Find this shape… …replace with this shape

19. 4. Shape Synthesis

20. Examples of designs generated via application of three shape rules

21. 5. Further Work How can we reduce the cognitive effort required of the designer?

22. Thank You