At the connectivism conference George Siemens responded to my posts on 'communication while using technology in education'. Here is the link to his blog. I haven't worked my way through the post and interesting comments on his blog completely yet, but it captures a number of important issues. I cannot see a true dialogue in blogging: online communication is not a true two-way conversation, but people posting messages, putting forward their own viewpoint, the things they are interested in. The medium is not as well suited to communicating as a face to face environment and people only half-listen to the other persons point of view (especially when they are as long as the ones on his blog) or do not respond at all.
The problem with not responding at all is that the blogger becomes an information source in broadcasting mode, rather than a source of knowledge. I can understand that people at the centre of networks, the 'experts' (and I do believe this is the way the networks develop, not random nodes, but communities with expert(s) at the centre) cannot always continue to communicate; they will move on themselves as they learn more. Where does that leave the people at the periphery of the network? I would say with lots of information to digest and a need to not only mull it over in their own heads, but to comunicate with others.