This paper treats design of the built environment as a decision process and asserts the need for a more objective base for design decisions. A conceptual review of the designer's problem acknowledges the difficulty of resolving multiple objectives and considers the nature of the information available to the decisionmaker. The designer's formal design evaluation is related to the informal evaluations of the eventual users of his product. Users' responses are physiological, behavioural, and attitudinal. It is argued that the accumulating understanding of attitudinal responses to the built environment constitutes a potentially valuable information base for the designer's own evaluative decisions.
