Among the questions and responses to our panel on Mapping Lines of Influence (Hyperlinked Society), two stick out. The first was a comment from David Weinberger who pointed out that there is a great mass of the blogosphere that is not represented by the type of graph that I used to map the blogosphere. It occurred to me that different algorithms for projecting graph data have similar consequences to different projections for physical maps. I haven't yet stumbled on a solution to this problem. The mass of the blogosphere that is missing is missing due to their low linkage.
The second was a comment from Jeff Jarvis about where discussion of influence should be concentrated. Jeff referred to a post he made on 'the magic middle', aka 'the big butt' of the blogosphere. While I basically agree that this area is extremely interesting, it still remains that the network effects between the head and the middle give tremendous influence to the A-list (a term which is, perhaps, losing currency). The graphical analysis that I've presented here before, and which I used in the panel, shows clearly that the magic middle (the communities outside the blogosphere's core on topics like knitting, cooking, etc.) are very much aware of the core.
One thing I have to do to update my analysis is to include directionality in the display of the link structure. I am still making an assumption about the directionality of links in the map (i.e. that the peripheral communities link in to the core). It should be relatively straightforward to fix this. If my assumption is incorrect, then we should see something quite fascinating: communities that the core refers to but which do not give any link-love back.