Logos decorate and epitomize. Those I've done each depict some facet of the project it identifies.
Diagrams can clarify otherwise complex relations, whether temporal, spatial, or conceptual.
Prototypes depict the future. I've made them with HTML, Java, PowerPoint, and GUI layout tools.
Languages let users say things, whether in static text or a dynamic GUI. I have designed both.
Information delivery should exploit graphic elements; see these papers and presentations.

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