Design decision-making is, if addressed properly, a hugely, complex multi-variety, multi-person process on which precious little serious research has been focused. In the late 1960's the Design Methods Group in the USA and the Design Research Society in the UK formulated paper-based models of the design process and anticipated, in some regards with un-nerving accuracy, the way in which the application of information technologies would impinge beneficially on the process of design decision-making and, therefore, on the quality of the built environment.

One concept expressed at that time was as follows: (•) the application of computers to the modeling and prediction of the cost and performance behavior of alternative design solutions allows subjective value judgements to be better informed and more explicitly audited, and that (•) such subjective value judgements should be made by those most affected by them, i.e. the future owners and users of buildings. //

This paper is devoted to the critical re-examination of this concept, on the seminal research and development which has kept the notion alive over 30 years, and, most importantly in the context of the theme of ACADIA 1999, how the current advances in multimedia, virtual reality and internet access are not yet making its ubiquitous adoption inevitable: in short, a plea for Media in Mediation.