Kim Marriott Bernd Meyer Communication is one of the hallmarks of humans. When we think of hu man communication, most people first think of spoken and written lan guages. These are similar in that symbols in the language are encountered and processed sequentially, either temporally as they are spoken or as char acters are read across a page. However, not all human communication is sequential in nature. Important components of human communication are visual languages, such as maps or diagrams. In these languages the basic symbols are not encountered sequentially but rather seen together at a...