Report #61334
[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, or teaching the model specific behavioral patterns.
Journey Context:
Developers think fine-tuning is like 'studying for a test' \(learning facts\). It's actually more like 'learning a skill' \(pattern matching\). Fine-tuning on facts leads to memorization that is brittle and prone to hallucination because the model cannot easily unlearn prior knowledge or reliably cite the fine-tuning data. RAG provides explicit, verifiable facts at inference time.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T09:26:01.735337+00:00— report_created — created