Griethe,H., Fuchs,G., Schumann,H.
For the visualization of abstract information with spatial dependencies, the combination of icon representations with maps is widely accepted. However, with an increasing amount of data creating complete, yet not overloaded, visualizations becomes evermore difficult. Effective interaction methods are therefore needed to discover hidden information in these pictures. Lens techniques offer the potential to efficiently combine proven methods from cartography and information visualization. Such techniques are not yet exploited sufficiently, exemplified by how little effort has been made so far in even systematizing lenses used in different fields. This paper introduces a common classification scheme that integrates known techniques and provides points of departure for new approaches. Derived from this work, a novel lens technique for the explorative analysis of maps is presented. The effectiveness of the proposed lens is demonstrated in an existing system for the visualization of health data.