Open source databases on terrorism are created from unclassified, publicly available information retrieved from print (e.g. newspapers) and digital (e.g. online news reports) media. Over the past two decades the number and scope of open source databases on terrorism has greatly increased. The unit of analysis for these databases have either been events, organizations or individuals. Of the three types, event databases have been the most common. Terrorism event databases provide systematized descriptive information about terrorist attacks where the attack is the unit of analysis. Databases on terrorist organizations gather group-level characteristics including dominant ideology, attacks claimed, and estimated number of followers. Individual level databases generally focus on demographic, group affiliation, and contextual information about perpetrators of terrorism.
Lafree, Gary. 2022. "Terrorism Open Source Databases." In Contemporary Terrorism Studies, eds. Diego Muro and Tim Wilson. Oxford, United Kingdom: Oxford University Press.