A reference map is a map that emphasizes the geographic location of features. These are some characteristics of reference maps:
- They display a variety of information.
- The primary aims are legibility and graphic contrast.
- No graphics marks (that is, symbolized points, lines, or polygons; text; or raster pixels) should be given visual emphasis over others.
For these maps, the goal is to display a lot of different kinds of information without drawing the reader's attention to any one theme of information more than any other theme. The reader can therefore direct their attention to the theme or themes of interest. For example, if the reader is using the reference map for navigation, they will direct their attention to roads and landmarks. If the reader is using the map for recreational purposes like hiking, then features on the map, such as contour lines and trails, will hold more interest for them.
For reference maps, the challenge is to figure out which classes of features are of greatest interest and use to a wide range of users (that is, what to include on the map.) In contrast, for thematic maps the emphasis is on the geographic pattern of the feature attributes. The challenge in making this types of map is figuring out which features to include as the minimal required locational reference information (that is, what to exclude from the map.)