Explorer la persistance des ancres cartographiques dans les cartes pan-scalaires

Interactive maps such as Google Maps or OpenStreetMap offer new ways to explore geographic information by enabling continuous navigation across multiple levels of detail and diverse spatial contexts. They allow dynamic transitions from one space to another: from the real world to its representation, from a coarse overview to fine-grained details, and from one cultural or environmental setting to another (e.g., from a continental view to a neighborhood, from urban to rural landscapes). Through perception and memory, these transitions continuously reshape how users interpret both the current and future scenes displayed. Exploration leaves traces: previously seen views influence subsequent spatial understanding, revealing the role of memory in designing and using pan-scalar environments. In this thesis, I introduce the concept of cartographic persistence as the ability of spatial information to remain perceptually or cognitively stable despite cartographic abstraction. I argue that persistence plays a central role in linking the geographic organization of the map with ongoing mental construction during navigation. Elements that persist across zoom transitions act as pan-scalar cartographic anchors, structuring spatial orientation and supporting continuity of exploration. This work aims to better define these anchors and to understand how users orient—or become disoriented—in pan-scalar cartographic spaces. I argue that interactive map design must account not only for spatial hierarchies and visual generalization, but also for exploration memory, positioned between the cartographic and mental spaces. Spatial transitions require users to perform a reconciliation process, aligning changes on the map with their evolving mental representation. I illustrate these mechanisms through a series of disorientation scenarios. I then explore cartographic persistence through two experimental approaches combining map drawing, recognition tasks, and controlled variations of visual properties. First, I introduce a drawing-based methodology that captures perceptual salience at different scales without presupposing specific objects. I formalize four indicators — presence, intensity, anchorness, and persistence — to identify potential pan-scalar anchors across locations and styles. Second, I test the effects of intensity and persistence on spatial memory. The results reveal that intensity has a measurable impact on recognition performance, while persistence as manipulated in the experiment did not significantly influence short-term memory — leading to a discussion of longer-term temporal effects within the zoom dynamics. Finally, I discuss design principles and methodological guidelines for pan-scalar cartography, including how anchors and relational structures can be detected across scales, and how drawing-based interpretation can be leveraged to preserve cartographic identity and support dynamic, cognitively coherent multiscale exploration