Grounding

What it is

Grounding constrains a generated answer to evidence that was actually retrieved, so each statement can be traced back to a source. The mechanism is consistent across implementations: retrieve passages, generate only from them, and keep the mapping from sentence to source so a citation can be shown or checked.

Why it matters

Grounding is what turns a plausible answer into a checkable one, and it is the main lever teams have for reducing hallucination without retraining anything. Its ceiling, though, is the corpus. Grounding against documents that contradict each other produces confident answers drawn from the wrong source — the citation is real, the answer is wrong, and the system reports success. That ceiling is why reconciliation comes first.