The problem resides in how realistic these Computer Generated Models (CGM) are. Moss & Banks (1958) considered realism “the capacity to reproduce as exactly as possible the object of study without actually using it”. He considers that realism depends on: 1)The number of elements that are reproduced; 2) The quality of those elements; 3) The similarity of replication and 4) Replication of the situation. CGM respond well to these considerations, they can be very realistic. But, are they capable of reproducing the same impressions on people as a real space?

Research has debated about the problems of the mode of representation and its influence on the judgement which is made. Wools (1970), Lau (1970) and Canter, Benyon & West (1973) have demonstrated that the perception of a space is influenced by the mode of presentation. CGM are two-dimensional representations of three-dimensional space. Canter (1973) considers the three-dimensionality of the stimuli as crucial for its perception. So, can a CGM afford as much as a three-dimensional model?

The “Laboratorio de Experimentacion Espacial” (LEE) has been concerned with the problem of reality of the models used by architects. We have studied the degree in which models can be used as reliable and representative of real situations analyzing the Ecological Validity of several of them, specially the Real-Scale Model (Abadi & Cavallin, 1994). This kind of model has been found to be ecologically valid to represent real space. This research has two objectives: 1) to study the Ecological Validity of a Computer Generated Model; and 2) compare it with the Ecological Validity of a Real Scale Model in representing a real space.