In 2016 the International Peace and Security Institute hosted a symposium on ‘Countering Violent Extremism’ in Washington D.C. Over 250 leading policymakers, digital pioneers, religious leaders and development practitioners used Ethelo as an online tool to collectively evaluate a range of strategies. Experts identified the top strategies as well approaches regarded as ineffective. The platform revealed levels of disagreement and consensus on different ideas, as well as (unexpected) areas of difference and convergence between diverse participant subgroups.