The first question we have to address is about the relationship between the notion channels of communication and the theoretical-linguistic concept of medium. Before answering this question, let me first draw attention to the different loads which these terms carry in social-scientific practice. The term channel mainly brings to the forefront the technological, physical and material aspects of language use. In that respect, its meaning overlaps with one use of the term medium, as the usage of the latter seems mostly to hover between a number of possible meanings, ranging from the channels of communication over the institutions in which these channels are established to the discourse practices characteristic of the institutionalized media. Indeed, the term media studies covers the three meanings, although its referential scope appears to be largely restricted to the so-called mass media (radio, television and printed periodicals). There is also another tradition in the use of the term medium, one which one mostly comes across in linguistic research. In this tradition, medium refers almost exclusively to one aspect of situational variation in language use, crucially seen along the axes of a basic polarity between spoken and written language. It is the latter theoretical outlook which I will essentially take issue with here.