Yilin Gong

Yilin Gong, Siqi Wu

Recent advances in artificial intelligence (AI) have made timely, scalable, and effective fact-checking increasingly feasible. One such deployment is X's Community Notes, which provides the AI Note Writer API to enable end-to-end automated generation of contextual information. We present the first empirical analysis of AI fact-checkers and their contributions on Community Notes, examining four key dimensions: volume, velocity, variety, and veracity. We find that, between September 2, 2025 and May 9, 2026, 20 AI writers account for 14.2% of all submitted notes, with their daily share rising rapidly to 44.8% lately. AI writers are highly responsive, typically submitting notes within minutes of posts becoming available via the API. They also expand coverage, contributing notes to 16.8% of fact-checked posts, of which 74.4% are not checked by humans. Over time, AI writers become more prolific and responsive, with increasing coverage and discovery rates. Despite these advantages, their veracity remains mixed. Collectively, AI writers contribute a higher share of helpful notes while receiving a smaller share of human ratings, relative to their share of submitted notes. Controlling for the fact-checked post and note submission order, both AI and human writers exhibit a first-mover advantage, with earlier notes attracting more ratings. More importantly, AI-generated notes are less likely to be classified as helpful than those written by human experts, though they outperform those written by laypeople. Our findings provide new insights into the practical capabilities and limitations of AI-driven fact-checking, with implications for the design and governance of human--AI collaborative crowdsourced context systems.

Yilin Gong, Siqi Wu

Several major social media platforms have shifted toward crowdsourced fact-checking systems like Community Notes to combat misinformation at scale. However, these systems face criticism regarding which content is scrutinized and how visible that scrutiny is. To address these concerns, X allows users to request community notes for specific posts. When sufficient requests accumulate, X displays an alert, formalizing an interface cue intended to guide contributor behavior. In this study, we examine the effectiveness of request alerts. We infer the presence of request alerts at the time each note was written and identify 318 top writers who were repeatedly exposed to these alerts. Through analyzing their contributed 54,874 English notes written with and without request alerts, we find that at the individual level, writers fact-check more diverse and more political content under alerts. Nonetheless, at the collective level, these shifts direct contributions toward the already dominant Politics and Conflict category, thereby increasing content inequality within the Community Notes ecosystem. Finally, using a mixed-effects model that controls for both writer- and topic-level random effects, we estimate that notes written under alerts are between 8.4 and 20.2 percentage points more likely to be classified as helpful and thus visible to the public, compared to non-alerted notes. This visibility gain diminishes as topics diverge further from writers' prior interests, demonstrating a pivot penalty effect. Taken together, our findings show that request alerts function as an effective interface cue that increases both topical diversity and note visibility in Community Notes.