  Conversation requires a substantial amount of coordination between dialogue
participants, from managing turn taking to negotiating mutual understanding.
Part of this coordination effort surfaces as the reuse of linguistic behaviour
across speakers, a process often referred to as alignment. While the presence
of linguistic alignment is well documented in the literature, several questions
remain open, including the extent to which patterns of reuse across speakers
have an impact on the emergence of labelling conventions for novel referents.
In this study, we put forward a methodology for automatically detecting shared
lemmatised constructions -- expressions with a common lexical core used by both
speakers within a dialogue -- and apply it to a referential communication
corpus where participants aim to identify novel objects for which no
established labels exist. Our analyses uncover the usage patterns of shared
constructions in interaction and reveal that features such as their frequency
and the amount of different constructions used for a referent are associated
with the degree of object labelling convergence the participants exhibit after
social interaction. More generally, the present study shows that automatically
detected shared constructions offer a useful level of analysis to investigate
the dynamics of reference negotiation in dialogue.
