The Expanded Fourth Edition, 2003, of Structure of the Visual Book has been almost doubled in size to 432 pages. More than a revision, this is almost a new book within the previous. There are several new chapters. One is a 19 page essay on the books by Nathan Lyons. Sequence is discussed and illustrated through 16 photos from Lyons' books. The new fourth edition of Structure of the Visual Book has over 450 photographs of artists books from 148 contemporary book artists from around the world. This instructive guide to the concepts of visual books presents strategies for organizing pictures in the book format. This is a book on concepts, not how to bind. It is an approach that conceives the book as a visual object not by imposed decoration, but through understanding and applying structure. Group, series and sequence are elaborately discussed and diagrammed. Composing the book, as well as the pictures it contains, creates pacing in turning pages. Just as poetry and cinema are conceived in time, so is a book.