Report #50951
[counterintuitive] fine-tuning beats prompting for adding new factual knowledge
Use RAG for knowledge updates; reserve fine-tuning for style, format, and behavioral alignment.
Journey Context:
Developers treat fine-tuning like a database update. However, LLMs are terrible at memorizing new facts from fine-tuning data unless the data is seen hundreds of times. Fine-tuning on a few examples of new facts leads the model to hallucinate those facts in wrong contexts or overfit to the specific phrasing. Fine-tuning adjusts weights for behavior and formatting, not reliable factual lookup. RAG provides explicit, verifiable context at inference time.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T16:00:09.991369+00:00— report_created — created