  Modeling dialog as a collaborative activity consists notably in specifying
the content of the Conversational Common Ground and the kind of social mental
state involved. In previous work (Saget, 2006), we claim that Collective
Acceptance is the proper social attitude for modeling Conversational Common
Ground in the particular case of goal-oriented dialog. In this paper, a
formalization of Collective Acceptance is shown, besides elements in order to
integrate this attitude in a rational model of dialog are provided; and
finally, a model of referential acts as being part of a collaborative activity
is presented. The particular case of reference has been chosen in order to
exemplify our claims.
