  This paper describes the Spot the Difference Corpus which contains 54
interactions between pairs of subjects interacting to find differences in two
very similar scenes. The setup used, the participants' metadata and details
about collection are described. We are releasing this corpus of task-oriented
spontaneous dialogues. This release includes rich transcriptions, annotations,
audio and video. We believe that this dataset constitutes a valuable resource
to study several dimensions of human communication that go from turn-taking to
the study of referring expressions. In our preliminary analyses we have looked
at task success (how many differences were found out of the total number of
differences) and how it evolves over time. In addition we have looked at scene
complexity provided by the RGB components' entropy and how it could relate to
speech overlaps, interruptions and the expression of uncertainty. We found
there is a tendency that more complex scenes have more competitive
interruptions.
