The Base Rate Project aims to develop the first estimates of a number of common risk factors/indicators for engagement in violent extremism. Specifically, we seek to (a) establish the rate at which these indicators occur in a general population sample, and (b) compare these with an existing population of lone-actor terrorists. To do so, we undertake a test of survey methods to first establish which is best. We compare an indirect questioning design, the Unmatched Count Technique (UCT), with a direct questioning design, in an online survey of 2,108 subjects from the general population.