EFFECTS AND EXPLANATIONS OF REFLECTIVE THINKING AND VERBALIZING IN DESIGN PROBLEM SOLVING
 
Wetzstein, A., Hacker, W. and Schroda, F., Technical University of Dresden, Germany
 
According to experienced engineering designers the dialog with a colleague, who is not familiar with the problem is one of the most important possibilities to support design problem solving. We asked, whether the dialogue-relevant language pattern, promoting descriptions, explanations, and justifications, indicates a specific rationalized type of processing, which is responsible for this result. The impact of different types of verbal reflection about the finished solution on the improvement of the design and its possible explanations were investigated. In a series of experiments 168 subjects had to sketch an everyday object. Answering heuristic wh-questions with and even without a partner as describing, explaining and justifying a finished design produces a significant improvement of the solution quality in contrast to the request to think again about the finished solution without speaking aloud. The types of the modifications of the solutions after the intervention differ significantly depending on the type of intervention. Answering solution-relevant heuristic wh-questions helps to identify solution gaps, produces explanations, especially of the functions of the designed object, and leads to proportionately more new and alternative solutions. The development of these improvements needs time, but this time consumption does not explain the effect. Verbalization supports focusing attention on the components of the problem and its relationships, and produces a more complete problem decomposition. These activities give rise to a specific type of intellectual processing, due to the dialogical language patterns, which improve the design process and quality.