The Role of the User in Generalization within Geographic Information Systems

At present, most GIS fail to take adequate account of the problems of generalization. The reason for the difficulty in generalizing in an automated environment is the complexity of the generalization process and, to an extent, the subjectivity of the process as carried out on data before it is encoded. An ideal generalization procedure within a GIS would select the best available generalization process based on purpose, scale, data types and quality requirements. Also, it would keep track of the changes operated upon the data by the generalization procedures. The aim, ultimately, is to rely as much as possible on a knowledge-based system to carry out this process for the user. But at the moment, knowledge-based generalization is severely limited and so any successful generalization within a GIS will need to depend heavily on the input of the user. The user interaction with each function of such a generalization system is described from the point of view of the user. The flexibility of the system to support different user views and the importance of friendly user interfaces is stressed