Since 1970, the Global Terrorism Database has collected more than 150,000 individual data points on acts of terrorism. Watch the video below, and you'll have a good idea of how terrorism developed globally according to the largest and most consolidated database in existence.

At first glance, it seems as if terrorist activity is growing dramatically - as the death toll, particularly in Iraq, Afghanistan and Nigeria has grown exponentially in the past decade.

But how do we know that's really the case?

An important lesson of data journalism: Always look at how the database was constructed.

In this case, any interpretation based on the obvious growth in terrorism might be misleading, as the database is old and has had numerous methodological amendments as well as lived through incredible technological innovations.

Here's why we shouldn't be so quick to jump to conclusions:

The database was started in 1970. And you can imagine the data collection process back then might have looked something like this:



Overdramatised recreation

Fast forward to today, into a world of globally integrated media enterprises and machine learning algorithms. So if a car blows up in rural Pakistan, the database may not have captured it as an event in 1983, but they certainly will have known about it today.

The advent of the internet, globalised media and social media have all had significant impacts on observable year-to-year trends in the data, especially as these have developed asymmetrically across the globe.

In this graph, we see how the number of sources used in the database fits snuggly to the number of deaths by terrorist acts.



The GTD is the most comprehensive and widely used dataset on terrorism by policymakers and journalists. Unfortunately they don't always read the fine print and instead take the data at face value. Such conclusions drawn on "hard data" can easily be abused by influential people looking for "evidence" to support fear-mongering strategies. Let's be vigilant, fellow data journalists :).

Data Source: "National Consortium for the Study of Terrorism and Responses to Terrorism (START). (2017). Global Terrorism Database [Data file]. Retrieved from https://www.start.umd.edu/gtd"