It is recognised that the traditional methods of requirements capture are not suitable when applied to ubiquitous and collaborative systems. With these sorts of systems what is important is an understanding of the social characteristics of work itself as well as the people who operate in the work environment. User-centred design and evaluation approaches have been used to do this however these approaches may not be straightforward in situations where perceptive technology is involved. The purpose of this workshop is to bring multi-disciplinary researchers together in order to discuss different models and theories that can be used to design and evaluate ubiquitous and collaborative systems. Particularly, the focus of the third International Workshop on Ubiquitous and Collaborative Computing (iUBICOM) is on user-centred design and evaluation of ubiquitous and collaborative computing including ethnography.