elearnspace points to a useful presentation by Barry Wellman in Social Networks for Newbies:
A terrific introduction to social network analysis: Social Networks Analysis for Newbies (.ppt). On a side note, SNA is a new addition to most corporations. Elearning faced an interesting battle in finding its place most organizations - technology or training department. SNA will be similarily confused - is it a training concern? or knowledge management? IT? or strategic (i.e. a C-level activity)?
I loved the in a nutshell description of why network analysis is so interesting: "To Discover How A, Who is in Touch with B and C, Is Affected by the Relation Between B & C" credited to John Barnes. Another version flashed through my mind that simply removed the direct connection from A to C: What part of the relationship between B and C commutes through to A? How is A enhanced by the fact that B and C have some relationship, when A is only directly connected to B?
Wellman has been doing this type of sociology research for many years. SNA is both new and old, as you will see in flipping through this presentation. SNA has certainly been helped by technical advances and more discussion about the importance of networks in our lives.
Towards the middle, there is the connection to KM in one of the research questions: "Knowledge Management: How do people find and acquire usable knowledge in networked and virtual organizations?" How do all these networks overlap and get things done (or hinder getting things done)? You've got the formal organization chart, friendships, and historical connection (historical org charts, for example). Then you have the business processes, information required for those processes, tools that supply / store / massage that information, the people who use the tools, and the people connected to the processes. And there are always more ways to slice this pie.
Update 6 Apr 2005: Fixed a broken link to Wellman's home page.