Content zooming and exploration for mobile maps

��� In the context of the development of mobile map applications with capabilities for map generalization and abstraction, we propose a methodology for content exploration that uses content zooming as a technique to change the degree of abstraction of map content independently of the map scale. We concentrate on „foreground data‖ (rather than the base map, or map background), and more precisely on POI data and thus on point generalisation. Content zooming provides the user with the capability to change the amount and the granularity of foreground information presented, while keeping the geometric map scale the same. Content zooming allows overriding the effects of ‗standard‘ map generalisation, focusing on optimised content representation to aid the information seeking task of a mobile user. It is thus complementary to map generalisation. Three cases of content zooming operations are distinguished: two cases apply changes to the amount of foreground data presented, while the third case changes the granularity of the foreground data. The paper defines these cases and proposes technical solutions for each of these, illustrating them with examples from a research prototype.