  An idealized, though simplistic, view of the referring expression production
and grounding process in (situated) dialogue assumes that a speaker must merely
appropriately specify their expression so that the target referent may be
successfully identified by the addressee. However, referring in conversation is
a collaborative process that cannot be aptly characterized as an exchange of
minimally-specified referring expressions. Concerns have been raised regarding
assumptions made by prior work on visually-grounded dialogue that reveal an
oversimplified view of conversation and the referential process. We address
these concerns by introducing a collaborative image ranking task, a grounded
agreement game we call "A Game Of Sorts". In our game, players are tasked with
reaching agreement on how to rank a set of images given some sorting criterion
through a largely unrestricted, role-symmetric dialogue. By putting emphasis on
the argumentation in this mixed-initiative interaction, we collect discussions
that involve the collaborative referential process. We describe results of a
small-scale data collection experiment with the proposed task. All discussed
materials, which includes the collected data, the codebase, and a containerized
version of the application, are publicly available.
