Spreadsheets augment a visible tabular layout with invisible formulas. Direct manipulations of the tabular layout may or may not result in the desired changes to the formulas. The user is forced to explore the individual cells to find, verify, and modify the formulas, which causes heavy cognitive overhead. We present a set of techniques that make these formulas and their resulting dataflow structure easily accessible while maintaining the natural appearance of the spreadsheet. Transient local

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... ews visualize dataflow structures associated with individual cells, while static global views and animated global explanations visually present the entire dataflow structure at once. Semantic navigation enables the user to navigate through the dataflow structure interactively, and visual editing techniques make it possible to construct formulas using graphical editing techniques. Central to these techniques is the use of animation and lightweight interaction for rapid and non-intrusive visualization. Our prototype implementation suggests that these techniques can greatly improve the expressive power of current spreadsheets as well as other applications that have rich underlying structures.