  This study is focused on the role of external representations, e.g.,
skteches, in collaborative architectural design. In particular, we analyse (1)
the use of graphico-gestural modalities and, (2) the articulation modes between
graphico-gestural and verbal modalities in design interaction. We have
elaborated a first classification which distinguishes between two modes of
articulation, articulation in integrated activities versus articulation in
parallel activities.
