I guess there’s a difference between “communication” and “attempting to communicate”, which if fails is better known as directed noise. If someone talks to you in a language you don’t understand, that’s I guess “attempted communication”…for it to be “communication” there needs to be coordination to form common knowledge

But I know what you mean…as you are forming the common knowledge (doing the coordination part in order to communicate) isn’t this coordinating act done by communicating…as you say it does seem to be interrelated.

Whether you’ve known someone for a short time or long time doesn’t matter…you could be explaining something new to your partner, something she knows nothing of…you first give them some establishing information so they are more equipped to understand what you are going to communicate (but as you say this coordination process involves communication itself)

When we say “…do you know what I mean”, is often a sign that we have not coordinated a good enough common knowledge, and only attempted communication has taken place.

Like you say stigmergy is indirect communication. Now do ants require coordinating a common knowledge..I don’t think so as they are rule-based…so I guess stigmergic communication doesn’t involve coordination..I’m just winging it here BTW

Yet ants appear to highly coordinate, but I think this is because they follow simple rules…it doesn’t seem to be similar to the notion or to the calibre as humans coordinate

http://en.wikipedia.org/wiki/Autocatalysis
“A single chemical reaction is said to have undergone autocatalysis, or be autocatalytic, if the reaction product itself is the catalyst for that reaction.”

I like this aligns with the question you pose “Can stigmergy be the autocatalyst for communication?”

You say “but how is communication being agreed upon”

It seems there’s no agreeing between multiple agents, as it’s up to the individual ant to make a decision based on the pheromone trace