ABSTRACT
Researchers and various agencies have attempted to capture the nature of SDI in definitions and models produced in various contexts. In particular the umbrella and building block views of SDI provide both a top-down and bottom-up approach to model SDI development in a hierarchical manner (Rajabifard et. al., 1999). Th e productional perspective of SDI also provides a conceptual tool that draws on the GIS literature to model SDI development (Chan et al., 2001). In this perspective SDI is described as a composite entity that is made up of modules of corporate GIS that assume the role of either a business process or an infrastructure in a spatial information industry.
