Report #69254
[counterintuitive] Should I fine-tune an LLM to add new domain knowledge
Use RAG for new factual knowledge; reserve fine-tuning for shaping output format, tone, and teaching the model how to use tools or knowledge it already possesses.
Journey Context:
Developers treat fine-tuning like studying a textbook, assuming the model will memorize and recall new facts. In reality, fine-tuning is like learning an accent or a skill. LLMs are notoriously bad at recalling precise facts from fine-tuning data and will still hallucinate. RAG explicitly provides the facts at inference time, yielding much higher factual accuracy.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T22:43:35.717461+00:00— report_created — created