Data science is a systematic process for applying techniques from statistics, data mining, and machine learning to solve complex problems. In this talk, Dr. Megan Squire will explain how she uses data science to understand complex socio-technical phenomena such as extremist group membership and the spread of dangerous propaganda. Dr. Squire's work of understanding online radicalization and measuring extremism on social media has been featured in numerous media publications including the BBC, NPR, The Economist, and on NBC News.