Context The Global Terrorism Database (GTD) was developed to be a comprehensive, methodologically robust set of longitudinal data on incidents of domestic and international terrorism. Its primary purpose is to enable researchers and analysts to increase understanding of the phenomenon of terrorism. The GTD is specifically designed to be amenable to the latest quantitative analytic techniques used in the social and computational sciences. Content The GTD was designed to gather a wide variety of etiological and situational variables pertaining to each terrorist incident. Depending on availability of information, the database records up to 120 separate attributes of each incident, including approximately 75 coded variables that can be used for statistical analysis. These are collected under eight broad categories, as identified in the GTD Codebook, and include, whenever possible: incident date region country state/province city latitude and longitude (beta) perpetrator group name tactic used in attack nature of the target (type and sub-type, up to three targets) identity, corporation, and nationality of the target (up to three nationalities) type of weapons used (type and sub-type, up to three weapons types) whether the incident was considered a success if and how a claim(s) of responsibility was made amount of damage, and more narrowly, the amount of United States damage total number of fatalities (persons, United States nationals, terrorists) total number of injured (persons, United States nationals, terrorists) indication of whether the attack is international or domestic Other variables provide information unique to specific types of cases, including kidnappings, hostage incidents, and hijackings. Acknowledgements Information in the GTD is drawn entirely from publicly available, open-source materials. These include electronic news archives, existing data sets, secondary source materials such as books and journals, and legal documents. All information contained in the GTD reflects what is reported in those sources. While the database developers attempt, to the best of their abilities, to corroborate each piece of information among multiple independent open sources, they make no further claims as to the veracity of this information. Users should not infer any additional actions or results beyond what is presented in a GTD entry and specifically, users should not infer an individual associated with a particular incident was tried and convicted of terrorism or any other criminal offense. If new documentation about an event becomes available, an entry may be modified, as necessary and appropriate. As discussed in more detail below, the first phase of data for the GTD (GTD1: 1970-1997) was collected by the Pinkerton Global Intelligence Service (PGIS)—a private security agency. Cases that occurred between 1998 and March 2008 were identified and coded by the Center for Terrorism and Intelligence Studies (CETIS), in partnership with START. A third data collection phase was instituted for cases that occurred between April 2008 and October 2011, with efforts led by the Institute for the Study of Violent Groups (ISVG) at the University of New Haven. Beginning with cases that occurred in November 2011, GTD data collection is done by START staff at the University of Maryland. In addition, GTD researchers have worked to supplement information on additional cases throughout the full duration of the GTD. In addition to data originally collected by PGIS, CETIS, and ISVG, cases identified in other archives of terrorism incidents have also been incorporated, including: Global terrorism incident data provided by Alex P. Schmid, Director of the Terrorism Research Initiative (TRI). We thank Prof. Schmid for allowing us to draw from databases he developed in the course of his career in academia and in the United Nations. Maghreb & Sahel Terrorism: Addressing the Rising Threat from al-Qaeda and other Terrorists in North & West/Central Africa, by Yonah Alexander Political Violence and Terrorism in Modern America, by Christopher Hewitt the Conflict Archive on the Internet the Australian Turkish Media Group and, Armenian Terrorism: The Past, Present, the Prospects, by Francis Hyland Further Submissions and Responses by the ANC to Questions Raised by the Commission for Truth and Reconciliation 12 May 1997 For More Information: http://www.start.umd.edu/gtd/