In thisarticle, we comparefeedback-related multimodal behaviours in two different types of interactions:first encounters between two participants who do not know each in advance, and naturally-occurring conversations between two and three participants recorded at their homes. All participants are Danish native speakers.Theinteractions are transcribed using the same methodology, and the multimodal behaviours are annotated according to the same annotation scheme.In the study we focus on the most frequently occurring feedback expressions in the interactions and on feedback-related head movementsand facial expressions. The analysis of the corpora,while confirming general facts about feedback-related head movements and facial expressions previously reported in the literature, also shows that the physical setting, the number of participants, the topics discussed, and the degree of familiarity influence the use of gesture types and the frequency of feedback related expressions and gestures.