Freeman’s Approach to Degree Centrality:
 Centrality is based on connections between nodes in the network
 Measure indegree and the outdegree and degree percentage of entire network for each node
 Can measure network statistics such as mean, standard deviation, etc.
 Network Centralization calculation compares a network to the perfect star network of the same size
 A star network of size N (nodes)
 Has one node whose indegree is N1 and whose outdegree is 0
 Other N1 nodes have outdegree 1 and indegree 0
 Network Centralization = (N * D – m) / ((N1)(N2)) where N is the number of nodes, D is the max degree whether that is in or out, and m is the number of edges
 A star network of size N (nodes)
For more information:
 http://www.faculty.ucr.edu/~hanneman/nettext/C10_Centrality.html#Freeman
 http://sna.cs.ccu.edu.tw/centrality_slide.pdf
References to use of this measure in literature:
 Collaboration and Integration of CommunityBased Health and Human Services in a Nonprofit Managed Care System
 Interorganization Relationships Among HIV/AIDS Service Organizations in Baltimore: A Network Analysis

Cheryl Alexander, Marina Piazza, Debra Mekos, Thomas Valente, Peers, schools, and adolescent cigarette smoking, Journal of Adolescent Health, Volume 29, Issue 1, July 2001, Pages 2230, ISSN 1054139X, DOI: 10.1016/S1054139X(01)002105.
(http://www.sciencedirect.com/science/article/B6T8043B290W4/2/8290dfdd3eb3d2e76e0fc7ec07681abd)