The ability to quickly explore and compare multiple scenarios is an important component of exploratory data analysis. Yet today's interfaces cannot represent alternative exploration paths as a branching history, forcing the user to recognize conceptual branch points in a linear history. Further, the interface can only show information from one state at a time, forcing the user to use her memory to compare scenarios. Our system includes a tree-structured visualization for navigating across time and scenarios. The visualization also allows browsing the history and selectively undoing/redoing events within a scenario or across scenarios. It uses the AI formalism of contexts to maintain multiple, possibly mutually inconsistent, knowledge base states. Cross-context formulas can be written for explicit scenario comparison, including visualizations of scenario differences.

Note: OCR errors may be found in this Reference List extracted from the full text article. ACM has opted to expose the complete List rather than only correct and linked references.

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