ABSTRACT
The common case with spatial data is that the given spatial position is the attribute of primary importance because the central tasks revolve around understanding spatial relationships. In these cases, the right visual encoding choice is to use the provided spatial position as the substrate for the visual layout, rather than to visually encode other attributes with marks using the spatial position channel. For datasets with spatial semantics, the usual choice for arrange is to use the given spatial information to guide the layout. The field of computer graphics addresses the problem of simply drawing geometric data. What makes geometry interesting in a vis context is when it is derived from raw source data as the result of a design decision at the abstraction level. A common source of derived geometry data is geographic information about the Earth. Cartographers have grappled with design choices for the visual representation of geographic spatial data.
