My eyes hooked on the following sentence in Katherine Hayles' book My mother was a computer: 'Beds, even more than telegraph offices, are notorious sites of the exchange of information.' (p.83) Beds as medium 
unorthodox but true, not only in the literature narratives Hayles talks about.
Perhaps I just made things too difficult regarding what we call a medium. I concluded it was impossible to define medium universally applicable but now I doubt. Why not defining a medium as any site (state, thing, place) which enables the exchange (coding/decoding) of information? It can be a tool, a device, a system, electricity, light, a bed, a body… Depending on the context anything can function as a medium, and thereby becoming a medium. Mediation then is an intricate process in which something is functioning as a medium. Another universal definition…
Still, the reduction of a process (of mediation) to a state, thing or place can be seen as ontologizing. The above universal definition of medium is in fact a definition of ontologized media. Though ontologizing is a productive epistemological movement, I still hold that this movement should not be reproduced in the analytical concepts which serve to clarify the processes involved. Mediation then is a better starting point.
So, we have recognized ontologized media (the raw material by which remediation as conceived by Bolter and Grusin operates, which I extended with a notion of demediation), and we have 'becoming media', the translation of anything into a medium, which I dubbed transmediation.
Intermediation – which was the term I thought I 'invented' in my earlier notes and did give a lecture about, is then the whole system of ongoing mediations (i.e. remediations, demediations and transmediations).
Surprisingly Hayles comes up with the same term, in the context of what she analyzes as the interactions of different worldviews of code, of writing, and of speech: 'These complex and entangled interactions are what I call ?intermediation,? a term suggested by Nicholas Gessler.' (p31).
Damn it, I did not invent the term 
