Research on misinformation has mostly focused on social and alternative media. By contrast, we know little about the extent of misinformation in mainstream media. While many argue that it acts as a gatekeeper, others think it could amplify the reach of misinformation. This study investigates misinformation on public broadcasting television. By semi-automatically matching fact-checked claims with statements from the subtitles of four German news and six talk shows, the study examines the dynamics of these claims. It finds 77 matches in 67 episodes, amounting to 4.85% of the 1382 episodes during the sampling period between June 2023 and June 2024. The rate is higher for talk shows (11.62%) than for news shows (2.28%). The claims cover a range of topics and often aim to destabilize trust in public institutions or discredit the political course of opposing parties. In most cases, they are made by politicians from populist or (far) right parties. In about half of cases, the claim is contradicted by the journalist or talk show guest, but often it is left uncommented, even if the claim was fact-checked before or the speaker was already known to have made the claim. The match rate for fact-checking organizations increases with their affinity for checking claims made by public figures. At the same time, the study finds no evidence that misinformation from anonymous online sources has infiltrated public broadcasting. This speaks against an amplification effect and points to a separation between online misinformation and that found on public television.
