How can we induce social media users to be discerning when sharing information during a pandemic? An experiment on Facebook Messenger with users from Kenya (n = 7,498) and Nigeria (n = 7,794) tested interventions designed to decrease intentions to share COVID-19 misinformation without decreasing intentions to share factual posts. The initial stage of the study incorporated: (i) a factorial design with 40 intervention combinations; and (ii) a contextual adaptive design, increasing the probability of assignment to treatments that worked better for previous subjects with similar characteristics. The second stage evaluated the best-performing treatments and a targeted treatment assignment policy estimated from the data. We precisely estimate null effects from warning flags and related article suggestions, tactics used by social media platforms. However, nudges to consider information's accuracy reduced misinformation sharing relative to control by 4.9% (estimate = -2.3 pp, s.e. = 1.0 , Z = -2.31, p = 0.021, 95% CI = [-4.2 , -0.35]). Such low-cost scalable interventions may improve the quality of information circulating online.

翻译：如何在疫情期间诱导社交媒体用户在分享信息时保持辨别力？一项针对肯尼亚（n = 7,498）和尼日利亚（n = 7,794）用户的Facebook Messenger实验，测试了旨在减少分享COVID-19错误信息意图，同时不降低分享事实性帖子意图的干预措施。研究初始阶段包含：（i）一个包含40种干预组合的析因设计；（ii）一个情境自适应设计，增加了对先前具有相似特征的对象效果更佳的处理措施的分配概率。第二阶段评估了表现最佳的处理措施及根据数据估算的目标性处理分配策略。我们精确估计了社交媒体平台使用的警告标志和相关文章建议策略的零效应。然而，引导用户考虑信息准确性的推动措施，相较于对照组，将错误信息分享减少了4.9%（估计值=-2.3个百分点，标准误=1.0，Z=-2.31，p=0.021，95%置信区间=[-4.2，-0.35]）。此类低成本可扩展的干预措施或可提升在线信息流通的质量。