Samenvatting

This article describes the value of the Global Terrorism Database (GTD) for the study of terrorist groups. The GTD helps to illustrate trajectories of violence of specific terrorist groups, helps to explore differences in terrorist violence between groups and between periods of time, and allows the testing of hypotheses concerning the origins and manifestations of terrorism. This article highlights the benefits of the GTD, using examples. The strengths of the GTD, but also opportunities for improvement are discussed.