AUTHORING GRAPHIC SCRIPTS - EXPERIENCES AND PRINCIPLES

Two prototype graphic scripts illustrate a variety of design principles useful in composing narrative sequences of dynamic maps, statistical graphics, and text blocks. The correlation script examines the variation and covariation of two variables in both geographic and bivariate attribute space, and the historical script uses complementary measurements to explore spatial-temporal change in a single variable. Both scripts are organized into acts and scenes, like a stage play, and progress from simple to more complex representations. A unique signature hue identifies each variable. Motion and juxtaposition link maps with scatterplots, bar graphs, and other noncartographic displays, and blinking symbols emphasize important features and support the sequential joint examination of maps and graphs by category or region. Text is a key element for describing the purpose or strategy of short graphic sequences, called graphic phrases, as well as for identifying variables, categories, or regions. Coherence requires a consistent and meaningful layout of graphic elements, the gradual introduction of new information in the context of more familiar material, and a concise statement of purpose for each section of the narrative. Promising future extensions and enhancements include adding an automatic voice-over composed of digitized or synthesized speech, which will allow the viewer to control the pace and direction of the presentation and to use various graphic phrases interactively, and tailoring the presentation to the viewer's experience and interests.