This map, a collaboration between the Esri Story Maps team and PeaceTech Lab, uses crowdsourced data from Wikipedia to present a chronology of terrorist attacks around the globe. Wikipedia moderators include experts in the field of global conflict and terrorism, and the pages driving this story have been revised thousands of times since the beginning of 2016. As a result, the quality of the data on this map is constantly improving.
As with any crowdsourced data, the map may display spurious or objectionable data, for which Esri and PeaceTech Lab hold no responsibility. Similarly, the definition of terrorism is inherently subjective, and in the case of this map is determined by the contributing community.