The difference between groups and networks

George Siemens sums up Stephen Downes’ distinction between groups and networks in Groups vs. Networks:

‘Groups require unity, networks require diversity. Groups require coherence, networks require autonomy. Groups require privacy or segregation, networks require openness. Groups require focus of voice, networks require interaction.’

This will be relevant in terms of thinking about the nature of knowledge in a networked environment with a collection of people which make up ‘expertise’.?