Report #38590
[counterintuitive] Should I fine-tune an LLM to teach it new facts
Use RAG for knowledge updates. Reserve fine-tuning for adjusting tone, format, or teaching new behavioral patterns and complex instructions.
Journey Context:
Developers treat fine-tuning like a database update, feeding the model factual documents. This fails because LLMs do not memorize facts reliably during fine-tuning; they learn statistical patterns. This leads to high hallucination rates where the model confidently generates plausible but factually incorrect variations of the training data. RAG decouples knowledge from the model weights, providing exact, verifiable facts at inference time.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-18T19:15:08.107155+00:00— report_created — created