From navigation aid to cognitive scaffold: mini-map as a tool for spatial working memory offloading in multiscale cartography

Abstract Mini-maps offer an overview of cartographic spaces, yet their cognitive role in information foraging and mental map construction remains debated. This study investigates the effectiveness of mini-maps in supporting wayfinding and information retrieval within multilevel cartographic interfaces. To this end, we employed a digit foraging-memorization task under a cumulative step-loading protocol. Participants explored a hierarchical spatial layout via pan-and-zoom interfaces, either with or without a mini-map. Behavioral data and recall feedback revealed that users increasingly relied on the mini-map for rapid navigation. In its absence, participants frequently reverted to earlier visualization tiers to compensate for the degradation of visuospatial memory. Notably, the benefits of the mini-map were amplified under high cognitive load, suggesting that it functions not only as a navigational aid but also as a cognitive scaffold-an external spatial memory buffer that reduces demands on the internal sketchpad of working memory. These findings highlight the mini-map’s potential as a task-contingent cognitive support in multilevel information visualizations, advocating for adaptive interfaces that adjust the mini-map availability in response to task load.