GroundingOverlapSignalScorer

Scores how much two propositions' grounding chunk ids overlap, as Jaccard similarity. Two propositions extracted from the same source chunks are more likely restating the same fact.

Abstains when either side has no grounding at all — there's no evidence to compare, so this stays out of the blend rather than counting as a mismatch. Weighted conservatively (0.5): shared grounding is corroborating, not conclusive — two different facts can be grounded in the same chunk.

Parameters