CS 790g Seminar: Complex Networks

Due on Wednesday Sep 16, 2009 at 2:30 pm

Social Network

1. Do an energy layout of the network using the Draw>Draw-Partition-Vector command, using the degree partition and either closeness or betweenness as the vector. Include an image.
2. Who is the most central node in the network by degree, closeness and betweenness?
3. Point out 3 vertices whose centrality scores differ (e.g. high betweenness but medium closeness) and explain from their position in the network why it happens.
4. Identify a node with high betweenness that you could afford to remove without disconnecting other vertices from that component. Create a second network that excludes that person. Use Net>Transform>Remove>Selected Vertices. Recompute betweenness for everyone remaining in the network. Include an image.
5. Point out 2 particular vertices and their position in the network. Discuss why their betweenness centrality score did or did not change.
6. Point out 1 vertex (if it exists) whose closeness centrality suffers as a result.
7. Briefly discuss the ambiguities (& missing data) in this kind of data collection.
8. Imagine you are a newcomer who wants to not only be friends with you, but occupy a central position in your network (I know, multiple personality is a bit hard to keep track of). You only have time to make 2 new acquaintances out of your network of friends. Which 2 would you choose to maximize your closeness centrality?
9. Add yourself to the network by using the command Net>Transform>Add>Vertices and adding edges in the Draw window and compute your closeness. Which 2 vertices would you connect to to maximize your betweenness score (what is your betweenness?).