  Studies related to crowds of pedestrians, both those of theoretical nature
and application oriented ones, have generally focused on either the analysis or
the synthesis of the phenomena related to the interplay between individual
pedestrians, each characterised by goals, preferences and potentially relevant
relationships with others, and the environment in which they are situated. The
cases in which these activities have been systematically integrated for a
mutual benefit are still very few compared to the corpus of crowd related
literature. This paper presents a case study of an integrated approach to the
definition of an innovative model for pedestrian and crowd simulation (on the
side of synthesis) that was actually motivated and supported by the analyses of
empirical data acquired from both experimental settings and observations in
real world scenarios. In particular, we will introduce a model for the adaptive
behaviour of pedestrians that are also members of groups, that strive to
maintain their cohesion even in difficult (e.g. high density) situations. The
paper will show how the synthesis phase also provided inputs to the analysis of
empirical data, in a virtuous circle.
