Interactive abstraction control in visualization systems

The construction of data visualization systems providing interactive control over the different detail levels at which such data can be observed is a complex and time-consuming task. In this paper, an approach to provide a reusable object-oriented support for this functionality is presented. The approach is based on the concept of abstractor objects, which provide the generic behavior to implement visualizations with semantic zooming externally controlled by the user through the use of abstraction scales. With this support, complex visualizations can be implemented independently from the management of the detail level that can be shown in different stages of the visualization. The design of a generic support for this functionality and examples of its use in two visualization tools, MetaExplorer and CityVis, are described. These examples have shown the versatility of abstractors to reduce the complexity of implementing new visualizations, promoting cleaner designs that increase, in consequence, the resuability of such visualizations.