The Design of Everyday Things

Norman introduced the concepts of affordances, signifiers, mapping and feedback to a popular audience and argued that when people struggle with designed objects, the fault lies with the design, not the user. The book was originally titled The Psychology of Everyday Things and the rename to Design was itself a design decision — clarity over cleverness. For product direction it is the canonical text on why usability matters and what specifically makes something usable or unusable; every designer knows the vocabulary, and every product director should. Read alongside Gould and Lewis's Designing for Usability for the academic origin and Alexander's Notes on the Synthesis of Form for the deeper theory. Norman's revised 2013 edition is the one to read.