Unlike Polis, Twitter’s project needs to find consensus, not for one question at a time, but for every conceivable controversy on the platform. Community Notes does this by estimating the diversity of viewpoints of participants, based on how different users rate the usefulness of other people’s notes. Twitter’s version of bridging the gap is to find notes deemed helpful by reviewers who usually disagree on much, suggesting they have different points of view. This technique, which is central to Polis and Community Notes, is called bridging-based ranking. Megill believes Twitter’s team has taken it to new technical heights. “Birdwatch has made a major breakthrough in scaling up these kinds of systems for a larger population and a wider range of problems,” he says.
So said Twitter’s vice president of product early this month that use of Community Watch has risen recently, but the project is still in its infancy. The data is open source, and as of Nov. 8, there were only 38,494 notes from 5,433 people — a small group to oversee on a platform with more than 200 million users. Nor can bridging-based ranking change human nature. An independent study found that people are more likely to write notes on tweets expressing views that differ from their own. David Rand, one of the authors, concluded in the Financial times that “partisanship is a major driver of user engagement with Birdwatch.”
Twitter’s own recently released survey also reports a partisan divide, with far more Democrats than Republicans finding the notes helpful. But a majority of both groups thought the notes selected by the system were helpful rather than not helpful. And community notes were also seen to reduce how many users share tweets that are overshadowed by heavily cautionary notes. The project can also claim some notable, if anecdotal, victories: this month both the White House and Elon Musk deleted many scattered tweets after a Community Watch note brought up the missing context.
Perhaps Community Notes’ biggest weakness is also shared by Polis. “Those digital democracy platforms have no real authority,” Taiwanese parliamentarian Karen Yu told me. Polis still relies on politicians to turn into law the consensus it gets from citizens. Because a social platform’s users have so little power over the service they use, Community Notes is even weaker. With the flick of a wrist, Elon Musk could make it — and all of the community’s notes — disappear.
But I don’t think he will. An old joke on Twitter, attributed to Mark Zuckerberg, says that the company’s management was so stupid that “they drove a clown car into a gold mine and fell into it.” Elon Musk may have driven into his own gold mine with his own clown car. It seems unlikely that he knew Birdwatch existed before buying the platform, but he stumbled across one of the most exciting content moderation innovations to ever come out of not just Twitter, but any major platform.
For Musk, who has burdened Twitter with debt, there’s a lot to like in Community Notes. It’s scalable, algorithm-driven, and doesn’t require legions of content moderators. Most importantly, it transfers the responsibility for determining the truth from Twitter itself to its users.
