Environmental psychologists specializing in architectural psychology offer "user needs' assessments" and "post occupancy evaluations" to facilitate communication between users and experts. To compare the efficiency of building descriptions, building walkthroughs, regular plans, simulation, and direct, long-time exposition, evaluation has to be evaluated.

Computer visualizations and virtual realities grow more important, but studies on the effects of simulation techniques upon experts and users are rare. As a contribution to the field of architectural simulation, an expert - user comparison of CAD versus endoscopy/model simulations of a Vienna city project was realized in 1995. The Department for Spatial Simulation at the Vienna University of Technology provided diaslides of the planned city development at Aspern showing a) CAD and b) endoscopy photos of small-scale polystyrol models. In an experimental design, they were presented uncommented as images of "PROJECT A" versus "PROJECT B" to student groups of architects and non-architects at Vienna and Salzburg (n= 95) and assessed by semantic differentials. Two contradictory hypotheses were tested: 1. The "selective framing hypothesis" (SFH) as the subjective theory of planners, postulating different judgement effects (measured by item means of the semantic differential) through selective attention of the planners versus material- and context-bound perception of the untrained users. 2. The "general framing hypothesis" (GFH) postulates typical framing and distraction effects of all simulation techniques affecting experts as well as non-experts.

The experiment showed that -counter-intuitive to expert opinions- framing and distraction were prominent both for experts and lay people (= GFH). A position effect (assessment interaction of CAD and endoscopy) was present with experts and non-experts, too. With empirical evidence for "the medium is the message", a more cautious attitude has to be adopted towards simulation products as powerful framing (i.e. perception- and opinion-shaping) devices.

Since the 1960’s as planning and community design decision making has become increasingly contentious, the American legal system’s adversial approach to conflict resolution has become the dominant model for public decision making. The legal system’s adversial approach to adjudication is essentially a zero-sum game of winners and losers, and as most land-use lawyers will agree, is not a good model for the design of cities. While the adversial approach does not resolve disputes it rarely creates a positive and constructive consensus for change. Because physical planning and community design issues are not only value based, community design through consensus building has emerged as a new paradigm for physical planning and design.

The Environmental Simulation Center employs a broad range of complementary simulation and visualization techniques including 3-D vector based computer models, endoscopy, and verifiable digital photomontages to provide objective and verifiable information for projects and regulations under study.

In this context, a number of recent projects will be discussed which have explored the use of various simulation and visualization techniques in community design. Among them are projects involved with changes in the City’s Zoning Regulations, the community design of a major public open space in one of the region’s mid-size cities, and the design of a new village center for a suburban community, with the last project employing the Center’s userfriendly and interactive 3-D computer kit of parts. The kit - a kind of computer “pattern book” is comprised of site planning, urban and landscape design and architectural conventions - is part of the Center’s continuing effort to support a consensus based, rather than adversial based, public planning and design process.