Report #73505
[counterintuitive] Fine-tuning LLMs to inject new factual knowledge
Use RAG for new facts; use fine-tuning only for style, format, or behavioral alignment.
Journey Context:
Developers assume fine-tuning works like human studying. In reality, LLMs struggle to memorize new facts via fine-tuning without severe overfitting and hallucination. The model distributes weights across the new text, leading to high confabulation when asked to recall specifics. RAG explicitly separates retrieval from generation, giving the model the exact fact in context.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T05:58:24.060619+00:00— report_created — created