This contribution analyses verbal interactions between diabetic patients and between healthcare professionals and patients, in a context of written electronic communication. Our socio-discursive and pragmatic approach involves examining exchanges in social networks in which patients, relatives and carers share their peri-medical culture, as do healthcare workers engaged in therapeutic education. We focus here on the negotiation of meaning and the construction of reference between these different actors; more specifically, we analyse, on the one hand, cases of conversational misunderstanding and non-understanding and, on the other hand, the discursive strategies implemented with the aim of explaining some complex disciplinary content, most often conveyed by scientific or medical terms, sometimes in a foreign language. Certain socio-discursive practices are particularly relevant, such as the various forms of discursive ergonomics: reformulations, translations, reorganisation of content, and so on. These are situated between the two principles of approximation and explicitness. We emphasise that these exchanges constitute a dialogical appropriation of knowledge, in other words a form of peer learning.
