The contribution initially invited from me was psychology and design, which should be a broad enough brief to satisfy any author. However, the theme of this book is design method, and to concentrate on applied psychology alone seems unjustifiably limited in this design method context. Neither the user nor the designer of a product or a production machine limits his actions or responses to the psychological plane. The human factors side of this field must be concerned also with anatomical, anthropometric and physiological aspects, as well as the sociological and other areas examined in other chapters. Therefore, to embrace these related biological sciences, I propose to discuss ergonomics and design.