Report #80657
[counterintuitive] Should I fine-tune an LLM to teach it new facts
Use RAG for knowledge updates; reserve fine-tuning for style, format, and behavior modification.
Journey Context:
Developers treat fine-tuning like a database update. Fine-tuning adjusts weights, which is great for changing the distribution of outputs \(e.g., learning to output JSON, or adopting a persona\). However, training on raw facts forces the model to compress discrete data into continuous weights, leading to high hallucination rates when recalling those specific facts. RAG provides exact text at inference, bypassing the compression loss.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T17:58:59.715125+00:00— report_created — created