  Automatic analysis of human behaviour is a fundamental prerequisite for the
creation of machines that can effectively interact with- and support humans in
social interactions. In MultiMediate'23, we address two key human social
behaviour analysis tasks for the first time in a controlled challenge:
engagement estimation and bodily behaviour recognition in social interactions.
This paper describes the MultiMediate'23 challenge and presents novel sets of
annotations for both tasks. For engagement estimation we collected novel
annotations on the NOvice eXpert Interaction (NOXI) database. For bodily
behaviour recognition, we annotated test recordings of the MPIIGroupInteraction
corpus with the BBSI annotation scheme. In addition, we present baseline
results for both challenge tasks.
