Decisions taken in the ‘private design space’ of the design team or ‘actor’ are closely related to the type of support that can be provided by a Collaborative Design system: automatic checks performed by activating procedures and methods, reporting of 'local' conflicts, methods and knowledge for the resolution of ‘local’ conflicts, creation of new IT objects/ building components, who the objects must refer to (the ‘owner’), 'situated' aspects (Gero and Reffat, 2001) of the IT objects/building components.

Decisions taken in the ‘shared design space’ involve aspects that are typical of networked design and that are partially present in the ‘private’ design space. Cross-checking, reporting of ‘global’ conflicts to all those concerned, even those who are unaware they are concerned, methods for their resolution, the modification of data structure and interface according to the actors interacting with it and the design phase, the definition of a 'dominus' for every IT object (i.e. the decision-maker, according to the design phase and the creation of the object). All this is made possible both by the model for representing the building (Carrara and Fioravanti, 2001), and by the type of IT representation of the individual building components, using the methods and techniques of Knowledge Engineering through a structured set of Knowledge Bases, Inference Engines and Databases. The aim is to develop suitable tools for supporting integrated Process/Product design activity by means of a effective and innovative representation of building entities (technical components, constraints, methods) in order to manage and resolve conflicts generated during the design activity.

Decisions taken in the ‘private design space’ of the design team or ‘actor’ are closely related to the type of support that can be provided by a Collaborative Design system: automatic checks performed by activating procedures and methods, reporting of 'local' conflicts, methods and knowledge for the resolution of ‘local’ conflicts, creation of new IT objects/ building components, who the objects must refer to (the ‘owner’), 'situated' aspects (Gero and Reffat, 2001) of the IT objects/building components.

Decisions taken in the ‘shared design space’ involve aspects that are typical of networked design and that are partially present in the ‘private’ design space. Cross-checking, reporting of ‘global’ conflicts to all those concerned, even those who are unaware they are concerned, methods for their resolution, the modification of data structure and interface according to the actors interacting with it and the design phase, the definition of a 'dominus' for every IT object (i.e. the decision-maker, according to the design phase and the creation of the object). All this is made possible both by the model for representing the building (Carrara and Fioravanti, 2001), and by the type of IT representation of the individual building components, using the methods and techniques of Knowledge Engineering through a structured set of Knowledge Bases, Inference Engines and Databases. The aim is to develop suitable tools for supporting integrated Process/Product design activity by means of a effective and innovative representation of building entities (technical components, constraints, methods) in order to manage and resolve conflicts generated during the design activity.

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.

The principal item of a full-scale lab preferably features a court-like facility where the 1:1 simulations are performed. Such lab facilities can be found at various architecture education centers throughout Europe. In the early eighties the European Full-scale Modeling Association (abrev. EFA, full-scale standing for 1:1 or simulation in full-scale) was founded acting as the patron of a conference every two years. In line with the conference title "Full-scale Modeling in the Age of Virtual Reality" the participants were particularly concerned with the relationship of physical 1:1 simulations and VR. The assumption that those creating architecture provide of a higher degree of affinity to physical than to virtual models and prototypes was subject of vivid discussions.

Furthermore, the participants devoted some time to issues such as the integration of model-like ideas and built reality thus uncovering any such synergy-effects. Thus some major considerations had to be given to the question of how the architectís model-like ideas and built reality would correspond, also dealing with user-suitability as such: what the building artist might be thrilled with might not turn out to be the residentsí and usersí everyday delight. Aspects of this nature were considered at the îArchitectural Psychology Meeting” together with specialists on environment and aesthetics. As individual space perception as well as its evaluation differ amongst various architects, and these being from various countries furnishing cultural differences, lively discussions were bound to arise.

In times characterized by the growing “architectural criticism” to the same extent as by the helplessness of the anonymous user the communication process between contractors, planer and users gains in importance. If communication is successful will not only depend on the quality of the project but also on the means of conveyance, e.g. visualizing or model representation. Can planning evaluation be effectively supported by virtual reality (VR)?