In the introduction, Tufte characterizes his three books on information design as follows. The Visual Display of Quantitative Information is about pictures of numbers, i.e., depicting data and statistics. Envisioning Information is about pictures of nouns and visual strategies for design. Visual Explanations is about pictures of verbs, the representation of mechanism and motion, of process and dynamics, of causes and effects, of explanation and narrative. -- Source of annotation: Marvin or Ruth Sackner.