More than meets the eye. The role of visuals in science textbooks.

Visuals and visuality are an integral part of science; whether in the thinking of scientists, the portraying of their work, or in the teaching of science. This paper examines the role of visuals in university-level textbooks. Apart from the function usually associated with visuals--that of interest--graphic devices serve a wide range of functions--as many as 10 or 15, some of which are crucial to the scientific process. These functions include such items as elaboration and economy, understanding and remembering, persuasion and analysis. We will explore some of these functions as well as the different degrees of reality that various graphics contain. We will also analyze the critical relationship between text, visual, amd caption text; a relationship that is not fully appreciated by readers and writers alike. The paper further investigates such issues as linearity and branching in the text, plus the interaction between graphics. The final section discusses the relationship between genres (e.g., pictures and tables) and functions (e.g., remembering and problem-solving)