The Global Terrorism Database, 1970–2010

Terrorism event databases provide systematized descriptive information about terrorist attacks from unclassified sources making the attack the unit of analysis. These databases generally follow the classic journalistic format of providing information on who is responsible for an attack, what happened, where it happened, when it happened and to the extent that it is known, how it happened. There have been a dozen or more major 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 police reports or victim or offender surveys, event databases have come to fill an important role. At the present moment, the longest running, most comprehensive of these data bases is the Global Terrorism Database (GTD) maintained by the START Consortium at the University of Maryland. Because most terrorists seek publicity, event databases that rely on print and electronic media are likely more useful for studying terrorism than most other types of crime. Nevertheless, event data have important weaknesses, most notably media inaccuracies; conflicting information or false, multiple or no claims of responsibility; and government censorship and disinformation. We use the GTD to describe the characteristics of world-wide terrorism from 1970 to 2010. We conclude with some observations about the future of terrorism event data bases.