“…The decision on the selection and design of an appropriate spatial framework is a crucial issue in the model building process which affects both the interpretation and acceptability of the models (Openshaw 1977, Baumann et al 1988. GIS offers spatial (dis)aggregation capabilities as well as interactive graphics display possibilities which combined with rudimentary exploratory spatial data analysis provides a considerable power to design zoning systems meeting specific requirements (see Batty and Xie 1994a).…”