The diagram at the beginning of the "Dynamic Forms of Communication" section is exceedingly poorly designed. As best as I can tell, it's supposed to be a digraph where the nodes are the students, the instructor, and the content; and the edges are communication channels.
The problem is, instead of having edges going from student to content and teacher to content, they added another node labelled "both" and put edges pointing from that node to content. In a graph with only three nodes and no multiple edges, there's no excuse for introducing a "both" node. The diagram would have been… >>>
