"In response to high-profile attacks by violent extremists, the field of preventing and countering violent extremism (P/CVE) has drawn increasing attention and funding since the early 2000s. Today, countries in all regions across the globe have put in place dedicated policies and measures to prevent extremism and support deradicalization alongside evolving threat patterns. In addition, various other policy domains beyond P/CVE also aim to foster the peaceful coexistence of different groups and promote social cohesion, often sharing similarities with approaches in extremism prevention. But without a sound evidence base and careful consideration of (un-)intended effects, activities to prevent and counter violent extremism can do more harm than good. Evaluations can help stakeholders to assess the effectiveness of P/CVE activities and identify how they can be improved. Compared to other policy fields like public health or economic development, however, evaluation as a practice in P/CVE is less widespread and still faces many challenges. Building on existing comparative research, this report provides an overview of the state of P/CVE evaluation as well as its current challenges and outlines ways forward. The insights presented here are based on the first iteration of an online expert survey we conducted across 14 countries on five different continents: Australia, Bosnia and Herzegovina, Canada, the Czech Republic, Indonesia, Côte d’Ivoire, Kenya, the Netherlands, Norway, Singapore, Spain, Tunisia, the United Kingdom, and the United States." (Executive summary, page 3)