The Evolution of Terrorism Event Databases

Terrorism event databases provide systematized descriptive information about terrorist attacks from unclassified, open sources where the attack is the unit of analysis. There have been a dozen or more systematic efforts to build terrorism event databases over the past four decades. Because terrorism is a type of behavior that is difficult to study by more traditional means (e.g. police reports or victim or offender surveys), event databases have come to fill an important niche. Contemporary efforts to build event databases can be traced back to the late 1960s and are likely related to the introduction of satellites and portable video equipment—technology that made it possible to send instantaneously images of conflict and violence from any one place on the planet to any other place. Thus far the most comprehensive event databases have been the RAND Memorial Institute for the Prevention of Terrorism and the RAND Database of Worldwide Terrorism Incidents (MIPT-RDWTI), the International Terrorism: Attributes of Terrorist Events (ITERATE), the Global Terrorism Database (GTD), the terrorism data collected by the US State Department, and the World-Wide Incidents Tracking System (WITS). Given the often clandestine nature of terrorism, event data have important weaknesses, most notably media inaccuracies; conflicting information or false, multiple, or no claims of responsibility; government censorship and disinformation; and a lack of systematic empirical validation. Nevertheless, event databases on terrorism can be justified in part because most terrorists seek publicity. Likely future improvements include better coverage of domestic terrorism, more extensive automated coding, enhanced geo-spatial coding, and better linkages to related databases.