Gravity++: A graph-based framework for constructing interactive visualization narratives

Interactive visualizations play a key part in the exploration and analysis of data, and in the creation of visual data stories. This paper describes a new graph-based framework for developing interactive visualizations for creating coherent visual data stories. We have realized our framework in a prototype tool named Gravity++. Gravity++ uses a novel graph architecture for modeling interaction, data navigation, and changes in visual representation to better communicate findings to an audience. The combination of these graph models provides better support and flexibility for designing interactive visualizations, data navigation, and visual data stories. We demonstrate the applicability of this framework by two example usage scenarios. We also report on an evaluation study conducted with representative participants. All participants successfully created meaningful visual data stories with a high level of complexity. Our results also show that Gravity++ is easy to use and supports the understanding and sense-making of the visual data story creation process.