Towards a visual language to improve user access to geographical information system functionalities

In this paper an environment to specify, analyze and execute visual programs for Geographical Information Systems, NetGIS, is described. Th.e lack of sophisticated user interfaces is one of the major drawbacks to Geographical Information Systems (GIS), particularly for people without a sound background in computer science. The use of a visual language approach is proposed here in order to hide the plethora of basic GIS functions while providing ready-to-use tools to solve user's sub-tasks. NetGIS is based on the module concept, conceived as a software building block that implements a solution to a generaI subtask and is presented to the user through a structured icono Complex GIS queries or tasks can be carried out by interconnecting modules into flow networks, using a direct manipulation approach.