Stop, Verify, and Listen: HALT‑RAG Brings a ‘Reject Option’ to RAG
The big idea RAG pipelines are only as reliable as their weakest link: generation that confidently asserts things the sources don’t support. HALT‑RAG proposes an unusually pragmatic fix: don’t fine‑tune a big model—ensemble two strong, frozen NLI models, add lightweight lexical features, train a tiny task‑adapted meta‑classifier, and calibrate it so you can abstain when uncertain. The result isn’t just accuracy; it’s a governable safety control you can dial to meet business risk. ...