PHYSICAL MODELS AND DESIGN COGNITION: TRIANGULATING CONTROLLED LAB STUDIES WITH INDUSTRIAL CASE STUDIES Vimal Viswanathan a and Julie Linsey b Department of Mechanical Engineering, Texas A&M University, College Station, TX, USA. Email: a vimkucv@gmail.com, b jlinsey@tamu.edu Physical models are a potential tool which affects designers’ cognition, and very little quantified data exists about the use of physical representation within the idea generation process. Physical models are widely implemented in the engineering design process. There are conflicting results and guidelines about the implementation of these representations as a tool for idea generation. A prior controlled study demonstrates that physical models supplement designers’ incomplete and erroneous mental models, thereby leading to more functional ideas but does not cause design fixation. Another observation study indicates physical representations induce design fixation, thereby reducing the variety of ideas. This paper explores the seemingly conflicting results through a qualitative coding of industrial projects and innovative product design case studies. Consistent with prior laboratory studies, the results show that physical models support the mental models of the designer. Keywords: Design Fixation, Idea Generation, Mental Models, Physical Models. 1. INTRODUCTION Creativity and innovation play vital roles in the engineering design process. Prototyping is a potential aid that can support designer cognition and thereby spur novel ideas. Designers often use physical models in the idea generation process. Physical models range from very simple models used for the visualization of the idea to complicated three dimensional and fully functional prototypes. Figure 1 shows the various models used for OJex Manual Citrus Juicer by the designers [1]. It is important to identify when to implement physical models in the design process, given the cost and time associated with prototype construction [2]. For this purpose, it is essential to unveil the effects of physical modeling on designer’s cognition. A controlled laboratory study indicates that physical models supplement designers’ mental models, leading to higher quality ideas [3]. Contrary to this, an observational study indicates a high degree of design fixation associated with the use of physical models in practicing designers [4]. Due to these conflicting findings, physical models’ effects on cognition need to be identified. This paper triangulates the findings from controlled lab studies by the authors [3] to case studies of industry-sponsored teams and innovative products. Reports from industry-sponsored projects and reported innovative product development cases are used as data sources. A qualitative framework is used to analyze and code the data to obtain quantitative outcomes. The method followed and the results obtained are discussed in subsequent sections. Research into Design — Supporting Sustainable Product Development. Edited by Amaresh Chakrabarti Copyright © 2011 Indian Institute of Science, Bangalore, India :: Published by Research Publishing ISBN: 978-981-08-7721-7