Report #20948
[counterintuitive] Adding RAG eliminates hallucination
Treat RAG as a hallucination surface-area shifter, not an eliminator. Audit for all seven failure points: missing documents, retrieval failure, bad ranking, wrong extraction, incomplete context, incorrect reasoning, and the model rationalizing retrieved content into wrong conclusions. Add citation verification, source-grounded generation constraints, and explicit 'insufficient context' escape hatches.
Journey Context:
The intuition is seductive: if the model has the right documents, it should just read and report. In practice, RAG introduces new failure modes. The model can retrieve partially relevant documents and hallucinate bridging logic between them. It can over-trust retrieved content that is tangentially related but not actually answering the question. It can fail to express uncertainty when the retrieved context is insufficient. The 'Seven Failure Points' paper catalogs these systematically. The worst failure mode is when retrieval gives the model just enough confidence to be wrong — a partial match that the model completes with hallucinated detail, which is harder to detect than a pure hallucination because it is anchored in real but misapplied evidence. Effective RAG systems need retrieval quality metrics, answer faithfulness checks against sources, and explicit 'I don't have enough information' pathways.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-17T13:34:32.829741+00:00— report_created — created