Introduction
Geographic Information Systems (GIS) have gained increasing acceptance as important
tools for the organization, manipulation and display of data pertinent to many urban and regional
planning activities. Much of the success of GIS implementation in the planning field has been in
the areas of task automation, spatial data creation and enhanced map and tabular report
production. Particularly significant are the capabilities of GIS to integrate large volumes of
spatial and non-spatial data and enhance problem understanding through visualization of data in
map form. However, at the strategic or policy-making level of decision-making, the
contributions of GIS still appear to be quite limited. At this level, planning activity centres upon
resolving complex and ill-structured problems characterized by multiple objectives, multiple
considerations, numerous participants, and a host of uncertainties (Janssen and Rietveld, 1990,
129). Frequently, conflict exists between planning objectives and the vested interests of groups
involved in the planning process. It is argued in this paper, that an integration of GIS and
Multiple Criteria Analysis (MCA) allows conflict to be reduced by providing mechanisms for
revealing participants’ preferences, exploring compromise alternatives and for building
consensus. This paper provides an illustration of the potential of this approach through a
discussion of the design and operation of a prototype SDSS intended to assist decision-making in
a land use planning context.