Network Graph Chuck Alice Vertices Nodes Edges Links Bob

Chuck Alice Bob

Chuck Alice Bob

Apollo 13 Network Tom Hanks Bill Paxton The Green Mile Kevin Bacon Magnificent Desolation: Walking on the Moon The Green Mile Bill Paxton Kevin Bacon Beyond All Boundaries Demi Moore Gary Sinise The Human Stain Ed Harris

Apollo 13 Network Tom Hanks Bill Paxton Kevin Bacon Gary Sinise Ed Directed or Undirected? Gary Sinise Ed Harris

Apollo 13 Network Degrees Tom Hanks Bill Paxton Gary Sinise Kevin Bacon Ed Harris Bill Paxton Gary Sinise Degrees Tom Hanks Bill Paxton Gary Sinise Kevin Bacon Ed Harris 2 2 4 1 1

3 2 3 2 4 4 3 3

Apollo 13 Network Edges: 5 Total Possible Edges: 10 Density: 5/10 = 0.5 Tom Hanks Bill Paxton Kevin Bacon Gary Sinise Ed Harris

Nodes: 8 Edges: 12 Total Possible Edges: ?? # Nodes * (# Nodes -1) 2 (8*7)/2 = 56/2 = 28 Density: 12/28 = 0.43

A E D C F G Path Distance / path length Shortest path SIX cliques H B

Apollo 13 Network Tom Hanks Bill Paxton Kevin Bacon Gary Sinise Ed Find cliques Gary Sinise Ed Harris

B C A J I H K R G D Q L M F N P E O

J I H G K R L N Q A M F P E D O C B

P 1 J I O 1 H G Q 2 C 2 R D 3 R 1 Q G 2 F P J 2 I 2 D O H 2 =18/10 1.8 C

P 2 J I O 2 H G Q 3 C 3 R D 4 F 1 Q G 1 F P J 1 I 1 D O H 1 =18/10 1.8 C

F 1 J I O 1 H G Q 1 C 2 R D 2 R 2 Q G 3 F P J 3 I 3 D O H 3 =21/10 2.1 Hub - connects many people (like R) D O H 3 =21/10 2.1 C

J I H G K R L N Q A M F P E D O C B Hub - connects many nodes, like R Bridge - if you delete a bridge, the endpoints will lie in different components D O C B

Q A P E D O Subnetwork C B

Q A E D Egocentric network for D, diameter 1 C B

Q A E D Egocentric network for D diameter 1.5 (All of D’s friends and the connections between them) C B

111 Edges, 48 nodes 111/(48*47) = 0.05