Report #91928
[counterintuitive] Should I fine-tune an LLM to teach it new facts or domain knowledge
Use RAG for injecting new factual knowledge; reserve fine-tuning for adjusting tone, format, or teaching specific behavioral patterns.
Journey Context:
Developers treat fine-tuning like a database update, assuming updating weights with new documents will reliably store and retrieve those facts. LLMs are terrible at memorizing specific facts via fine-tuning; they generalize and blend weights, leading to high rates of confabulation for specific details. RAG explicitly separates the knowledge \(retrieved text\) from the reasoning \(LLM weights\), yielding much higher factual accuracy.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T12:53:37.501398+00:00— report_created — created