Report #62154
[counterintuitive] Should I fine-tune LLM to add new domain knowledge
Use RAG for knowledge updates and fine-tuning only for style, format, or behavioral shaping.
Journey Context:
Developers treat fine-tuning as writing to a database, assuming it reliably injects new facts. Fine-tuning adjusts weights to alter output distributions, making it excellent for teaching the model a specific tone or format. However, it is highly unreliable for knowledge injection; the model can memorize training data but often fails to generalize or accurately recall specific facts, leading to confident hallucinations. Updating knowledge requires expensive retraining, whereas RAG provides verifiable, easily updated facts.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T10:48:50.515069+00:00— report_created — created