"The research presented here proposes to examine the complexity of the mental representation of the city by means of the evaluation made by two different professional groups (one of experts in urban design, the other of non experts) of a series of significent city landmarks. We start from the assumption that the specialists in urban design will posess a different degree of complexity in their urban representation. To examine that differing complexity of representation, we have resource to a technique which, for all its difficulties in terms of implementation, offers a series of interesting possibilties, such as the "repertory grid" (Caputy and Keynes, 2001): it is a technique which does not impose limits of any kind when applied at an individual level and it is the subjects who are the objects of the research that freely provide us with the elements and constructs with which we are able to then work in a standard format applicable to all the subjects and allowing a comparison between them."