Aaron Heppleston

Often people are overwhelmed by the decision to buy a home because they are unable to find a consistent, reliable means of managing infonnation and assessing potential properties. It is surprising then that home-buyers have not been provided with access to computer-aided decision support, since its design allows users to input their unique preferences by selecting and weighting multiple criteria. Spatial decision support systems (SDSS) would be especially valuable to home-buyers as they can be used to incorporate spatial relations in the decision-making process. To demonstrate its benefits to a home- buyer a SDSS is created, combining a graphical user interface, a database management system and multiple-criteria decision-making techniques in a customized geographic infonnation system (GIS). Three types of spatial relations -location, proximityand direction -are examined in the decision to buy a home as well as non-spatial attributes commonly considered in the process. The SDSS is used in a case study with data provided by the Municipal Property Assessment Corporation (MPAC) for five hundred houses in the City of Toronto. Evaluation scores are calculated for each house before geographically-weighted averaging is applied to a decision rule that assesses and ranks candidates. Home-buying provides an example ofhow systems can be designed to aid decision-makers in the search for the ideal location and provides an opportunity to explore the contributions that spatial relations can make in the process, both as criteria and in the decision rule.