Identifying overlapping terrorist cells from the Noordin top actor - event network

Saverio Ranciati*, Veronica Vinciotti, Ernst C. Wit

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

1 Citation (Scopus)

Abstract

Actor-event data are common in sociological settings, whereby one registers the pattern of attendance of a group of social actors to a number of events. We focus on 79 members of the Noordin Top terrorist network, who were monitored attending 45 events. The attendance or nonattendance of the terrorist to events defines the social fabric, such as group coherence and social communities. The aim of the analysis of such data is to learn about the affiliation structure. Actor-event data is often transformed to actor-actor data in order to be further analysed by network models, such as stochastic block models. This transformation and such analyses lead to a natural loss of information, particularly when one is interested in identifying, possibly overlapping, subgroups or communities of actors on the basis of their attendances to events. In this paper we propose an actor-event model for overlapping communities of terrorists which simplifies interpretation of the network. We propose a mixture model with overlapping clusters for the analysis of the binary actor-event network data, called manet, and develop a Bayesian procedure for inference. After a simulation study, we show how this analysis of the terrorist network has clear interpretative advantages over the more traditional approaches of affiliation network analysis.

Original languageEnglish
Pages (from-to)1516-1534
Number of pages19
JournalAnnals of Applied Statistics
Volume14
Issue number3
DOIs
Publication statusPublished - Sep-2020

Keywords

  • Bayesian modeling
  • mixture models
  • MCMC algorithm
  • network
  • overlapping clusters
  • P-ASTERISK MODELS
  • STOCHASTIC BLOCKMODELS
  • MIXTURE MODEL
  • LOGIT-MODELS
  • INFERENCE
  • CRITERIA

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