Community Notes help prevent misinformation on X, study suggests

Community Notes, a fact-checking tool introduced on X under Elon Musk, appear to be working despite initial scepticism – but only if they’re timely.

Posts with Community Notes get less engagement and are less prone to going viral, a study led by researchers from the University of Washington (UW) has shown, with likes and reposts of such posts dropping 44% and 46%, respectively.

“We found that Community Notes are effective when attached, especially in reducing engagement that signals support for the content, such as reposts and likes,” said senior author Martin Saveski, a UW assistant professor in the Information School.

However, researchers found that for Community Notes to be effective, they had to be added quickly.

“Content spreads rapidly across X, and if a note comes too late, few users will get a chance to see it,” said the paper’s lead author, Isaac Slaughter, a UW doctoral student in the Information School.

“Notes that take 48 hours or so to go up have almost no effect,” he said.

The study also showed that notes were more effective on altered media, such as fake photos and videos, than they were with text-based posts.

Like studies before, the researchers stressed that just one tool is not enough to tackle misinformation. The spread of misinformation on social media is “complex and multifaceted, and it requires multiple approaches working together to effectively curb it,” Saveski said.

While engagement dropped significantly for reposts and likes, Community Notes were not as impactful when it came to replies and views.

“We think views were less affected because what users see is mostly decided by X’s feed algorithm,” Saveski said.

“From the public release of the algorithm, we know that X does not explicitly de-emphasize posts with notes attached, but that could change in the future.”

This may explain why X can still be a major source of misinformation and was even accused of playing a “central role” in inciting the UK riots in 2024.

Community Notes were first piloted by what was then called Twitter and introduced as the platform’s main tool of fact-checking when Musk took over in 2022 and laid off 80% of its content moderation team.

The tool allows users to add context and fact-check the original post. Other social media platforms, including Meta and YouTube, have introduced similar features.

UW researchers tracked 40,000 posts where a note was suggested, then monitored those with notes attached for 48 hours and compared them with posts that did not receive notes on two key aspects – engagement and virality.

“We found that Community Notes significantly change the way information spreads through a network. People who are distant in the social network from the person who posted the misinformation are much less likely to interact with the post. But people close to the source – followers, for instance – tend to be less affected by the note,” Slaughter said.

The team published the results of the study in Proceedings of the National Academy of Sciences of the United States of America.