The statistical data can be visualized as points, lines or areas. According to the selected representation feature, the Wizard directs the user to select the appropriate geometry type for his thematic map.

Representation feature = point
Geometry type = point It is recommended to load additional basemap layers (ex. countries) in step 5 to complete the map. Geometry type = polygon The symbols are placed on polygons' centroids. There is no need to add other basemap layers.
Representation feature = line
Geometry type = line It is recommended to load additional basemap layers (ex. countries) in step 5 to complete the map.
Representation feature = area
Geometry type = polygon There is no need to add other basemap layers.

Visit the OCAD Wiki for more information.