Viaggio starts his paper by pointing out the persistent underrating of the pragmatic aspect of communication in conference interpreting, an underrating that amounts to underrating relevance. He urges teachers of interpreting to make students aware of the interpreter’s task, i.e. make the speaker relevantly understood by his interlocutors. To this aim the author advances a model of communication, containing a number of truisms 1) on the speaker’s side, 2) between the speaker (and the mediator) and his addressee and 3) on the addressees’ side. These truisms serve as a basis for a definition of successful communication, a description of the obstacles to successful communication and a definition of successful mediated communication. A practical example is given to illustrate how relevant identity can be established on line.