Manual Participation Deception
RECRUITMENT
In total, 4.3% (294/6818) of randomized participants were identified as having engaged in manual participant deception during the entire recruitment period. As illustrated in Manual participant deception, bots, and actual recruitment throughout the study. CAPTCHA: Completely Automated Public Turing Test to Tell Computers and Humans Apart.Updating the advertising helped reduce the number of false responses but also reduced the number of genuine participants enrolling. Because of the impact on the recruitment of genuine participants, a third version of the advertisement was used, where compensation was mentioned but not given prominence (Figure S3 in The rate of manual participant deception was reduced as a result of further screening questions, diligent checks by the research team, and excluding false participants from the study. This fluctuated throughout the study (CONSORT (Consolidated Standards of Reporting Trials) diagram of participant numbers and reasons excluded.