A Protocol Analysis of Designers’ Reasoning and Fallacies in Design Concept Generation

Background To understand the design concept generation process inference, this study aims to identify the designer's reasoning process and the various aspects accompanying the fallacy. We tried to develop the classification scheme of fallacy applied schemes in argumentation rhetoric and cognitive psychology to explore the discriminability in designers’ reasoning. Methods Retrospective protocols were collected to analyze. First, two coding schemes of design activity elements and fallacies of designers’ reasoning in the design concept generation process were derived by examining domestic and foreign studies on design reasoning. Second, the designers’ fallacy classification system was proposed to embrace the characteristics of design reasoning, selectively resorting to the typological list. Third, we analyzed qualitatively and quantitatively the protocol data of design activities and fallacies classified according to the coding schemes. Results In this study, various aspects of design errors were empirically identified by applying the fallacy classification system to the design field. According to the results of the study, designers were using different reasoning strategies according to their preferred approach and engaging in the various fallacies, the design concept generation process. The difference in reasoning strategy also had a significant effect on the difference in the proportion of logical fallacy types. Conclusions The criteria and classification schemes established in this study systematically detected and identified the fallacies or errors in design reasoning, and their effectiveness in the design field was exploratively confirmed. These conceptual frames and schemes can be used effectively in the feedback to improve the quality of the designers' reasoning.