\input zb-basic \input zb-ioport \iteman{io-port 05993011} \itemau{Navarretta, Costanza} \itemti{Annotating non-verbal behaviours in informal interactions.} \itemso{Esposito, Anna (ed.) et al., Analysis of verbal and nonverbal communication and enactment. The processing issues. COST 2102 international conference, Budapest, Hungary, September 7--10, 2010. Revised selected papers. Berlin: Springer (ISBN 978-3-642-25774-2/pbk). Lecture Notes in Computer Science 6800, 309-315 (2011).} \itemab Summary: This paper deals with the annotations of non-verbal behaviours in a Danish multimodal corpus of naturally occurring interactions between people who are well-acquainted. The main goal of this work is to provide formally annotated data for describing and modelling various communicative phenomena in this corpus type. In the paper we describe the annotation model and present a first analysis of the annotated data focusing on feedback-related non-verbal behaviours. The data confirm that head movements are the most common feedback-related non-verbal behaviours, but they indicate also that there are differences in the way feedback is expressed in two-party and in three-party interactions. \itemrv{~} \itemcc{} \itemut{multimodal annotations; feedback; two-party and multiparty spontaneous interactions} \itemli{doi:10.1007/978-3-642-25775-9\_29} \end