STEVE INSKEEP, Host:
NPR's Tom Gjelten went to Fort Bragg in North Carolina to learn more.
TOM GJELTEN: The idea here is that a roadside bomb is never the work of one individual alone.
KATHLEEN CARLEY: Someone has to build it. Someone has to place it. Someone has to do surveillance on the place where you place it.
GJELTEN: Kathleen Carley, a professor of computer science at Carnegie-Mellon University, is the godmother of social network analysis as applied to the IED problem.
CARLEY: And if you're trying to defeat IEDs, what you're talking about is understanding that whole process - who is involved, how they're connected to each other - so that you can figure out where the best place is to intervene.
GJELTEN: In other words, if you're going to capture or kill one person in the IED network, who should it be to have the best chance of bringing the whole operation down? The answer may be found in mathematics. And at Fort Bragg, North Carolina, soldiers en route to Iraq are getting a crash course.
IAN MCCULLOH: So now you can do the relational algebra to have people associated by their common event, their common knowledge, or their common resource.
GJELTEN: The students are visualizing a network of all the people involved in an IED cell. On a computer screen, each one is a node, displayed as a dot linked by lines to other dots. Some individuals are more important than others, depending on their centrality score - basically how connected they are to others in the IED network.
MCCULLOH: You know, from these guys to these guys, it's a lot shorter to go through D than it is to go through E and F to get there, so that's what kind of gives D a high betweenness centrality. He's also connected to the most people. He also has an average shorter distance to everybody. So in many ways D is the highly central node.
GJELTEN: When the U.S. military is looking for key people to capture or kill, you do not want them to identify you as a highly central node. All the soldiers in Major McCulloh's class will have some role in the anti-IED effort in Iraq. Major Robert Cope will be at the headquarters of the 18th Airborne Corps.
ROBERT COPE: I'll be the counter-IED lead on the USFI staff.
GJELTEN: That's United States Forces Iraq.
COPE: And I'll be involved in the targeting. So this is - this will very much complement my tool kit.
GJELTEN: In truth, intelligence analysts have long understood the need to study enemy relationships. What's new is how sophisticated the process has become. Veteran analysts use hunches and intuition to construct the social network that lies behind a roadside bombing operation. But brainy warrior-mathematicians like Major McCulloh can do it far more quickly.
MCCULLOH: The first network I looked at probably had about two to three hundred nodes in it, and it took an analyst with 26 years experience about five days to look through it and identify where they felt the key vulnerabilities were, and I was able to put it into the software that I'm using and do some basic network analysis, and in about 15 to 20 minutes I kind of had the same conclusion.
GJELTEN: As with any computer operation, the quality of the analysis depends on the quality of the data going in. Kathleen Carley, who's worked with the military since she got out of college, says if soldiers are to understand a roadside bombing network, they need information, from people they capture, from informants, from intercepted phone calls.
CARLEY: You try to find things out about who else they know, who they're related to, where they've been in the past, where were they trained, what other kind of groups did they belong to, things like that.
GJELTEN: Major Eugene Vindman, a JAG officer, or judge advocate general, says he's taking Major McCulloh's network analysis course because it'll be better prepare him for his oversight responsibilities in Iraq.
EUGENE VINDMAN: Maybe do a little bit of analysis on your own or ask some intelligent questions of the targeteer, to make sure that the target they've identified is not a guy that might have made a wrong phone call to a bad guy but actually has enough links to that bad guy through other activities to actually be a bad guy and therefore be a legal military target.
GJELTEN: Tom Gjelten, NPR News.