On Reading Sketch Maps

A computer program, named MAPSEE, for interpreting maps sketched freehand on a graphical data tablet is described. The emphasis in the program is on discovering cues that invoke descriptive models which capture the requisite cartographic and geographic knowledge. A model interprets ambiguously the local environment of a cue. By resolving these interpretations using a new network consistency algorithm for n-ary relations , MAPSEE achieves an interpretation of the map. It is demonstrated that this approach can be made viable even though the map cannot initially be properly segmented. A thoroughly conservative, initial, partial segmentation is described. The effects of its necessary deficiencies on the interpretation process are shown. The ways in which the interpretation can refine the segmentation are indicated.