Terrorism studies has grown exponentially in the last decade. However, gaps still remain in the analysis of terrorism from the compilation of data to the examination of specific case studies in an effort to discern trends, such as in the radicalisation of individuals across cultural, religious, and gender lines. This book focuses on a central question that will be answered by a diverse group of academic and professional experts on terrorism: what are the current gaps in terrorism studies, and how can focusing on these gaps better inform our policy and operational decision-making. These experts provide their analysis of what is missing in the study of terrorist activities, groups, and the use of political violence. They also illustrate these gaps by applying theories that inform the understanding of terrorist behavior and focus on different paths of inquiry.