Interaction of Symbols is a book for everyone engaged with icon design. It presents a theory of how icons work: symbols in an icon interact to evoke meaning. From this theory flow design principles and practices based on evidence from Design and other disciplines such as Psychology, Perception and Cognition. The theory. principles, and practices impact how all symbol-based communications are conceived, designed, and applied The book focuses on icons that elicit a concept without any previous training or use of language. Findings from twenty years’ worth of empirical design research studies explore, illustrate, and support each principle, process, and recommendation. The book begins with a review of icon research from various fields before laying a conceptual foundation that grounds the theory of the book. After and elaborating on that theory are chapters that demonstrate how to Establish Contexts to Guide Comprehension, Glean Which Symbols to Draw, Learn How to Draw Understandable Symbols, Clarify Metaphor, and Use Icons to Decipher Icons in Icon Systems. Written and carefully designed for a broad audience, the book’s scholarly level is elevated while the presentation is approachable. Scholar or professional can skim, scan, or dig, it’s up to them. Heavily illustrated and supported with ample citations, it is not only a book for students and professionals within the field of communication design, but also for anyone who communicates with visual symbols, from healthcare professionals to software engineers, affecting all kinds of graphic communications from advertisements to assembly instructions.