Report #49898
[counterintuitive] fine-tuning for adding new knowledge
Use RAG for knowledge injection and fine-tuning for style, format, or tone adaptation. Fine-tuning is notoriously bad at injecting novel factual knowledge not well-represented in the base model's pre-training data.
Journey Context:
Developers often try to fine-tune a model on a proprietary codebase or document corpus, expecting it to 'learn' the facts. Fine-tuning optimizes weights for patterns, not memorization of specific facts. It is prone to overfitting on the training text without generalizing the underlying logic, leading to confident hallucinations of 'learned' facts. RAG is the correct tool for knowledge; fine-tuning is for behavior.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T14:14:23.165932+00:00— report_created — created