Abstract:
The use of a contextual reporting technique, to supplement the basic display of geographic data has been previously described (Gahegan, 1994; 1995). Standard forms of graphical and textual reporting are embellished with deductions regarding the significance of reported values, using automated reasoning to examine data within a defined context. This paper explores some of the different types of reporting behaviour that can be made available within a GIS, by defining context in terms of the geographic properties of data. Such a context may be defined over any group of geographic objects, and then specialised, using constraints in the spatial and temporal domains, or generalised, using the class specialisation hierarchy to examine progressively broader contexts. A brief formalism for geographic context is developed. Results are presented using a dataset of agricultural land and these show the adaptive nature of the reporting behaviour and demonstrate some of its potential uses. A discussion of the strengths and weaknesses of the approach is also given.
