Using grids in maps

Our approach aims at a general description that is common to all types of grids used in diagrammatic representations despite their individual differences. Based on our analysis, we specify different types of spatial knowledge and single out in which way a particular type of grid represents a particular type of spatial knowledge. This specification identifies the various contributions of grids to diagrammatic representations. It turns out that grids in maps and especially in schematic maps have two complementary functions. First, they enable inferences that are not possible using only the spatial map features. Second, they provide additional design freedom, as important information that is not represented in the schematic map itself, can be encoded in the grid structure