Users are shown messages via pop-up, email etc. that that forewarn and refute prevalent and potentially harmful misinformation narratives.

Note on terminology: some define prebunking to include content and tools that teach about common misinformation strategies and fact-checking techniques. You can see those interventions in our "Misinformation Literacy" library item.

Through preemptive exposure to fact-checked misinformation on a specific topic, users gain greater awareness and criticality towards misinformation they may see on that topic, and become less susceptible toward it.

In three separate studies, researchers found that providing periodic prebunking information improved users’ ability to discern between true and false content. 

In a study conducted in India by Garg and Yadav (2022), weekly text summaries of fact-checked misinformation were delivered to participants through a custom mobile app over ten weeks. By the end, the researchers noted a 19% increase in their ability to tell false from true news headlines, compared to a control group that did not receive the summaries; however, they also observed a 6% increase in skepticism towards both true and false news. (Note: all results we report in this review are statistically significant, unless otherwise stated. We also share results in the units reported by study authors.)

A second study by Batista et al. (2023) was conducted during the 2020 mayoral elections in Brazil. Participants were offered a voucher for a newspaper subscription that provided professional news coverage and fact checks of the main rumors in Brazil. Participants who used the voucher (about 13%) were less likely to accept rumors, as measured by pre and post surveys. (Note: because of the way the study was designed, the authors were able to use a statistical technique to verify that the voucher was effective, but it is difficult to interpret the effect size.) 

The third study by Bowles et al. (2023) was conducted in South Africa where bi-weekly fact-checks were delivered to participants over six months via Africa Check’s WhatsApp account. Participants received fact checks either as text messages or as one of three forms of podcasts of varying length and style. In an endline survey, participants who received any type of fact-check had an increased discernment between true and false information, compared to a control group (0.06 SDs). Participants were also better at identifying conspiracy theories (0.1 SDs) and had more knowledge of verification methods (0.1 SDs).

Together, these experiments present a consistent effect of prebunking on improved discernment between true and false content. Notably, the studies were conducted across three continents, pointing to the universality of this approach. However, we remain cautious about concluding that these interventions have an impact in practice as the studies are survey or quasi-field experiments and there is no indication the intervention has behavioral impacts (e.g. reducing how much individuals share misinformation). Furthermore, in addition to the increased skepticism of true news in the first study, the third study found effects that platforms may find undesirable such as decreased trust in social media (0.09 SDs) and lower intentions to share social media content (0.1 SDs).

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Misinformation is continuously evolving. Yet on important societal issues where there is a known prevalence of misinformation, prebunking can be a useful tool to prevent individuals from being susceptible to harmful misinformation.