In this fourth edition, Bryan Lawson continues his discussion, trying to understand how designers think. He does this by mapping out the issues concerned with the design process, with design problems and solutions and design thinking. This edition adds to the previous debates by including a new chapter on 'Design as Conversation' reflecting on how designers, either consciously or unconsciously, monitor, reflect on, control and change their thinking. It also includes a new series of case studies on notable designers including the racing car designer Gordon Murray, product designer James Dyson, and architects such as Edward Cullinan and Glenn Murcott. It presents a unique look at the psychology of the designer that provides a greater insight to the process of design. It demystifies the complexity of the subject and uncovers new ways that design can be done. It draws conclusions from years of research and provides the very latest debate on the subject.