Flagging Extremist Content

Great article from ASI Data Science on Binary Classification and ROC Curves.

It is well known that online propaganda from terrorist organisations plays a key part in radicalisation in Europe and the UK. In collaboration with the UK Home Office, we recently developed and tested an AI algorithm designed to detect such propaganda on the web.

Following media coverage of the classifier (see, for example, BBC News and The Guardian), there has been much talk of how it works and its performance. In this post, without exposing the inner workings of the algorithm, we’ll do our best to outline the general approach we took to design the classifier. We also specify precisely the metrics used and the performance achieved by the classifier.