|   | CMU-ISR-08-116 Institute for Software Research
 School of Computer Science, Carnegie Mellon University
 
    
     
 CMU-ISR-08-116
 
Social Network Change Detection 
Ian A. McCulloh, Kathleen M. Carley 
March 2008  
Center for the Computational Analysis ofSocial and Organizational Systems (CASOS) Technical Report
 
CMU-ISR-08-116.pdf Keywords: Social networks, change detection, statistical process
control, CUSUM, Al-Qaeda, IkeNet, terrorism
 Changes in observed social networks may signal an underlying change 
within an organization, and may even predict significant events or behaviors. 
The breakdown of a team's effectiveness, the emergence of informal leaders, 
or the preparation of an attack by a clandestine network may all be associated 
with changes in the patterns of interactions between group members. The 
ability to systematically, statistically, effectively and efficiently detect 
these changes has the potential to enable the anticipation of change, provide 
early warning of change, and enable faster response to change. By
applying statistical process control techniques to social networks we can 
detect changes in these networks. Herein we describe this methodology and 
then illustrate it using three data sets. The first deals with the email 
communications among graduate students. The second is the perceived 
connections among members of al Qaeda based on open source data. The 
results indicate that this approach is able to detect change even with 
the high levels of uncertainty inherent in these data.
 
26 pages 
 |