The Application of Expert Systems to Small Scale Map Designs

The increased availability of inexpensive computer mapping programs in recent years has lead to a great increase in the number of map authors and the number of maps being produced, but does not however appear to have lead to more widespread knowledge of cartographic design theory. The large number of poorly designed maps created by users of these computer systems indicates that there is a lack of knowledge of how to design maps. These poorly designed maps are not the fault of the computer programs, since most programs do have the capability of producing well designed maps when used by someone knowledgeable in map design. Rather, the problem lies with map authors who are not skilled in cartographic design and who would probably never produce a map by conventional means, but would contract a cartographer to produce it. What is required are programs to be used by naive map authors that are better able to produce reasonably well designed maps, or at least maps which do not break the most fundamental rules of map design. The area of computer science devoted to producing programs that include knowledge of how an expert solves a problem is that of Expert Systems. An Expert System is essentially a program which includes a codified form of the rules that an expert uses to solve a problem. Thus a cartographic design expert system would include the rules a cartographer uses when designing a map. This study examines the fields of artificial intelligence and expert system to assess how they may best be applied to the map design problem. A comprehensive review of the application of expert systems in design, mapping generally and map design in particular is also provided. In order to develop an expert system, the problem or 'domain' must be defined in a relatively formal manner. A structure for describing geographic information and cartographic representation is developed and a model of the cartographic design process for application in expert systems is also described. Based on the models developed, a functional specification for a cartographic design expert system for small scale maps is produced, with the rules required for each stage in the design process being set out. The development of an expert system, written in Prolog, incorporating these rules is then described in some detail. Details of how the Prolog language can be applied to a specific problem, colouring the political map, are also given. It has been found that as long as realistic goals are set and that the system is limited either in scale or range of topics, it is possible to develop an operational cartographic design expert system. However, it must be recognised that a considerable amount of further development will be needed to bring such a system to market with the support structures and robustness that this entails