Using Multiagent Systems Technology and Case-based Reasoning in the Valution of Residential and Office Properties

Property valuation is a particularly complex and large problem domain that requires diverse, highly sophisticated skills, expertise and knowledge. Experienced valuers have framed sets of assumptions to be applied in estimating the ‘most likely selling price’ or the ‘worth’ of a property. In order to implement a valuation, these valuers use mathematical models called ‘valuation methods’. Previous property valuation experiences hold a wealth of knowledge and expertise that can be often taken for granted. In the valuation of residential and commercial properties those experiences can play a crucial role in achieving an accurate most likely selling price’ or the ‘worth’ for the property being evaluated. But how can we empower computer-based valuation systems to acquire, store and use creatively this knowledge and expertise? Case-based reasoning is a technology for problem solving based on recall and reuse of specific experiences. Agent-based systems technology offers modularity and techniques for handling complexity, managing and searching information, and co-ordinating many different resources and integrating multiple sources of expertise. This paper makes an appraisal of valuation methods as used in Portugal’s property industry. It outlines how current case-based reasoning techniques and multiagent systems technology can be used to support the property valuation processes. Finally, it proposes a knowledgebased framework which combines case-base reasoning and multiagent systems technology for the valuation of residential and commercial properties.