Apriori, it seems that e-discussions are detrimental to maintenance of communication, hence, by definition, to intersubjectivity: In spoken discussions, joint attention is very often maintained. Turn-taking is central in this endeavor as turns are determined by facial expression, pause of the other, intonation, or simply interruption. Also, turn-taking in spoken conversation follows a normative ideal of precisely alternating turns. The word ‘precisely’ refers to the timing of the transition from one speaker turn to the next, which is ideally supposed to occur with no (or minimal) gap, and no overlap between speakers. ‘Alternating’ refers to the expectation that participants will take turns speaking in an orderly fashion; thus in dyadic exchanges, one person speaks, the other responds, the first speaks again, the second takes the following turn, and so forth. In small group conversation, overlaps can occur but they generally occur throughgestures, facial expressions, etc. In sum, numerous cultural tools are at the disposal of participants of spoken discussions in general and collective argumentation in particular, to maintain communication. In contrast, descriptive studies of computer-mediated communication (CMC) suggest that this maintenance may often turn out to be problematic. These studies exhibit numerous violations of both the “no gap, no overlap” principle and the principle of orderly turn alternation, unless floor control in turn-taking is ensured (automatically, by a tutor or by the discussants themselves). Concerning gaps, there is often a considerable time lag between when a message is sent and when it is responded to, especially in asynchronous forms of CMC. Synchronous CMC involves more rapid exchanges of turns, but delays may be caused by disrupted turn adjacency. Overlap in CMC is also problematic. In dyadic communication, users – unable to tell whether their interlocutor is in the process of responding or not –may become impatient and send a secondmessage before a response to the first has been received, resulting in incomplete or interleaved exchange sequences. In group communication, unrelatedmessages fromother participants often intervene between an initiatingmessage and its response. According to Herring, these problems are responsible for incoherence, and for topic decay — the fact that discussants rapidly discuss less and less the topic at stake during e-discussions. For us, these violations suggest that presence in an e-discussion maynot necessarilymean attendance, at least in real time, to turns. Of course, in spokendiscussions too, peoplemay not always notice that one of the interlocutors intervened, but this phenomenon is inherent to synchronous CMC: discussants do not feel obliged to answer a question directed to them, especially when they are busy answering to other participants.