"Human Behaviour in Design" addresses important aspects of creative engineering design. The main topics are the interaction between two complementary modalities - "image" and "concept", internal and external components of design thinking, and design strategies - both for individual designers and design teams. The goal is to improve and evaluate tools and methods that support design. Although this book is the outcome of an international workshop held in March 2003, it is more than just a collection of its contributions. The papers are arranged into three main topics: Individual Thinking and Acting; Interaction Between Individuals; Methods, Tools and Prerequisites. There are summaries of the discussions of the respective topics written by the chairpersons, conclusions, and an outlook to future issues in design research.