The effects of grid line separation in topographic maps for object location memory

Research from the field of cognitive psychology provides evidence that cognitive representations of space based on maps or map-like sketches are subject to systematic distortion tendencies. These distortions influence the orientation capacity as they represent errors in spatial memory. Map grids are a traditional feature of map graphics that has rarely been considered in research on spatial distortions in cognitive maps. Grids traditionally assist the map reader in finding coordinates and objects, but they also provide a systematic and homogeneous structure for dividing up map information into smaller units supporting perception and spatial memory. In a previous study it was shown that grids improve object location memory. The aim of this study was to determine whether different sizes of grid cells have an effect on the quality of object location memory. Therefore, an empirical study including the test performances of 33 participants was carried out: the memory performance was measured as both the percentage of correctly recalled object locations (hit rate) and the mean distance errors of correctly recalled objects (spatial accuracy). Three different intervals of grid line spacing (Separation) were applied to topographic maps. These maps varied in their type of characteristic geographical areas, accompanied by three different levels of map complexity (Landscape). The results of this study show that both factors have an impact on object location memory in topographic maps.