Report #65710
[counterintuitive] fine-tuning to add new knowledge facts
Use RAG for adding new factual knowledge; reserve fine-tuning for altering model behavior, tone, format, or teaching specific syntactic patterns.
Journey Context:
When developers need an LLM to know new domain-specific facts, they often fine-tune it on a dataset of question-answer pairs. LLMs are terrible at memorizing new facts through fine-tuning; they compress and interpolate the data, leading to high hallucination rates on exact factual recall. Fine-tuning adjusts weights for behavioral patterns, not lookup tables. RAG explicitly provides the facts in-context, guaranteeing higher fidelity and updatability.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T16:46:26.466089+00:00— report_created — created